Notes To Financial Statements [Abstract]
Notes to Financial Statements [Abstract]
Stock-based Compensation Expense
Schedule of Compensation Cost for Share-based Payment Arrangements, Allocation of Share-based Compensation Costs by Plan [Table Text Block]
Stock Option Activity
Schedule of Share-based Compensation, Stock Options, Activity [Table Text Block]
Summary Of Restricted Stock Units
Schedule of Share-based Compensation, Restricted Stock Units Award Activity [Table Text Block]
Summary Of Market-performance Based Restricted Stock Units
Schedule of Nonvested Performance-based Units Activity [Table Text Block]
Schedule of Share-based Payment Award, Employee Stock Purchase Plan, Valuation Assumptions
Schedule of Share-based Payment Award, Employee Stock Purchase Plan, Valuation Assumptions [Table Text Block]
Short-Term And Long-Term Marketable Securities
Available-for-sale Securities [Table Text Block]
Investments Classified by Contractual Maturity Date
Investments Classified by Contractual Maturity Date [Table Text Block]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block]
Financial Assets Measured At Fair Value On Recurring Basis
Fair Value, Assets Measured on Recurring Basis [Table Text Block]
Disclosure Inventories [Abstract]
Disclosure - Inventories [Abstract]
Raw materials
Inventory, Raw Materials, Net of Reserves
Work in process
Inventory, Work in Process, Net of Reserves
Finished goods
Inventory, Finished Goods, Net of Reserves
Total inventories
Inventory, Net
Marketable Securities and Fair Value Measurements
Financial Instruments Disclosure [Text Block]
New Accounting Pronouncements or Change in Accounting Principle [Table]
New Accounting Pronouncements or Change in Accounting Principle [Table]
Scenario [Axis]
Scenario [Axis]
Scenario, Unspecified [Domain]
Scenario, Unspecified [Domain]
Out of period adjustment
Scenario, Adjustment [Member]
Equity Components [Axis]
Equity Components [Axis]
Equity Component [Domain]
Equity Component [Domain]
Retained Earnings
Retained Earnings [Member]
Adjustments for New Accounting Pronouncements [Axis]
Adjustments for New Accounting Pronouncements [Axis]
Type of Adoption [Domain]
Type of Adoption [Domain]
Accounting Standards Update 2016-09
Accounting Standards Update 2016-09 [Member]
Accounting Standards Update 2016-09 [Member]
Accounting Standards Update 2016-16
Accounting Standards Update 2016-16 [Member]
Accounting Standards Update 2016-16 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Interest and other income (expense), net
Nonoperating Income (Expense)
Accrued liabilities
Accrued Liabilities, Current
Tax benefit
Effective Income Tax Rate Reconciliation, Share-based Compensation, Excess Tax Benefit, Amount
Effective Income Tax Rate Reconciliation, Share-based Compensation, Excess Tax Benefit, Amount
Decrease to retained earnings
Income Tax Effects Allocated Directly to Equity, Cumulative Effect of Change in Accounting Principle
Disclosure Long Lived Assets By Geographic Area [Abstract]
Disclosure - Long-Lived Assets by Geographic Area [Abstract]
Schedule of Segment Reporting Information, by Segment [Table]
Schedule of Segment Reporting Information, by Segment [Table]
Statement, Geographical [Axis]
Geographical [Axis]
Segment, Geographical [Domain]
Geographical [Domain]
United States
UNITED STATES
The Netherlands
NETHERLANDS
Mexico
MEXICO
Other International
Other International [Member]
Other International [Member]
Segment Reporting Information [Line Items]
Segment Reporting Information [Line Items]
Long-lived assets
Long-Lived Assets
Disclosure Total Estimated Annual Future Amortization Expense For Acquired Intangible Assets [Abstract]
Disclosure - Total Estimated Annual Future Amortization Expense for Acquired Intangible Assets [Abstract]
Remainder of 2017
Finite-Lived Intangible Assets, Amortization Expense, Remainder of Fiscal Year
2018
Finite-Lived Intangible Assets, Amortization Expense, Year Two
2019
Finite-Lived Intangible Assets, Amortization Expense, Year Three
2020
Finite-Lived Intangible Assets, Amortization Expense, Year Four
2021
Finite-Lived Intangible Assets, Amortization Expense, Year Five
Thereafter
Future Amortization Expense Thereafter
Future Amortization Expense, Thereafter
Net Carrying Value, ending balance
Finite-Lived Intangible Assets, Net
Income Statement [Abstract]
Net revenues
Revenue, Net
Cost of net revenues
Cost of Revenue
Gross profit
Gross Profit
Operating expenses:
Operating Expenses [Abstract]
Selling, general and administrative
Selling, General and Administrative Expense
Research and development
Research and Development Expense
Total operating expenses
Operating Expenses
Income from operations
Operating Income (Loss)
Net income before provision for income taxes and equity in losses of investee
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest
Provision for income taxes
Income Tax Expense (Benefit)
Equity in losses of investee, net of tax
Income (Loss) from Equity Method Investments
Net income
Net Income (Loss) Attributable to Parent
Net income per share:
Earnings Per Share [Abstract]
Basic (in usd per share)
Earnings Per Share, Basic
Diluted (in usd per share)
Earnings Per Share, Diluted
Shares used in computing net income per share:
Weighted Average Number of Shares Outstanding, Diluted [Abstract]
Basic (in shares)
Weighted Average Number of Shares Outstanding, Basic
Diluted (in shares)
Weighted Average Number of Shares Outstanding, Diluted
Commitments and Contingencies
Commitments and Contingencies Disclosure [Text Block]
Document Documentand Entity Information [Abstract]
Document and Entity Information [Abstract]
Entities [Table]
Entities [Table]
Legal Entity [Axis]
Legal Entity [Axis]
Entity [Domain]
Entity [Domain]
Document Information [Line Items]
Document Information [Line Items]
Trading Symbol
Trading Symbol
Entity Registrant Name
Entity Registrant Name
Entity Central Index Key
Entity Central Index Key
Current Fiscal Year End Date
Current Fiscal Year End Date
Entity Filer Category
Entity Filer Category
Document Type
Document Type
Document Period End Date
Document Period End Date
Document Fiscal Year Focus
Document Fiscal Year Focus
Document Fiscal Period Focus
Document Fiscal Period Focus
Amendment Flag
Amendment Flag
Entity Common Stock, Shares Outstanding
Entity Common Stock, Shares Outstanding
Disclosure Segments And Geographical Information Additional Information [Abstract]
Disclosure - Segments and Geographical Information - Additional Information [Abstract]
Number of reportable segments
Number of Reportable Segments
Stockholders' Equity
Disclosure of Compensation Related Costs, Share-based Payments [Text Block]
Disclosure Minimum Future Lease Payments For Non Cancelable Leases [Abstract]
Disclosure - Minimum Future Lease Payments for Non-Cancelable Leases [Abstract]
Remainder of 2017
Operating Leases Future Minimum Payments Due Remainder Of Period
Operating Leases, Future Minimum Payments Due, Remainder of Period
2018
Operating Leases, Future Minimum Payments, Due in Two Years
2019
Operating Leases, Future Minimum Payments, Due in Three Years
2020
Operating Leases, Future Minimum Payments, Due in Four Years
2021
Operating Leases, Future Minimum Payments, Due in Five Years
Thereafter
Operating Leases, Future Minimum Payments, Due Thereafter
Total minimum lease payments
Operating Leases, Future Minimum Payments Due
Other Commitments [Table]
Other Commitments [Table]
Business Acquisition [Axis]
Business Acquisition [Axis]
Business Acquisition, Acquiree [Domain]
Business Acquisition, Acquiree [Domain]
Belen Business Center
Belen Business Center [Member]
Belen Business Center [Member]
Range [Axis]
Range [Axis]
Range [Domain]
Range [Domain]
Maximum
Maximum [Member]
Counterparty Name [Axis]
Counterparty Name [Axis]
Counterparty Name [Domain]
Counterparty Name [Domain]
SDC
SDC [Member]
SDC [Member]
Other Commitments [Axis]
Other Commitments [Axis]
Other Commitments [Domain]
Other Commitments [Domain]
Commitments To Purchase Convertible Promissory Notes With Private Company
Commitments To Purchase Convertible Promissory Notes With Private Company [Member]
Commitments To Purchase Convertible Promissory Notes With Private Company [Member]
Other Commitments [Line Items]
Other Commitments [Line Items]
Loan facility
Loans and Leases Receivable, Commitments, Fixed Rates
Borrowing base as a percentage of accounts receivable
Loans and Leases Receivable, Borrowing Base As A Percentage Of Accounts Receivable
Loans and Leases Receivable, Borrowing Base As A Percentage Of Accounts Receivable
Stated rate
Loans and Leases Receivable, Commitments, Fixed Rates, Stated Rate
Loans and Leases Receivable, Commitments, Fixed Rates, Stated Rate
Advances outstanding
Loans and Leases Receivable before Fees, Gross
Commitment
Other Commitment
First note
Other Commitments, Future Minimum Payments, Remainder of Fiscal Year
Second note
Other Commitment, Due in Second Year
Third note
Other Commitment, Due in Third Year
Maturity date
Other Commitment, Maturity Date
Other Commitment, Maturity Date
Interest
Debt Instrument, Interest Rate, Stated Percentage
Software
Software Subscription Commitment
Software Subscription Commitment
Software term
Software Subscription Term
Software Subscription Term
Consideration
Business Combination, Consideration Transferred
First deposit
Escrow Deposit
Summary of Goodwill by Reportable Segment
Schedule of Goodwill [Table Text Block]
Schedule of Amortized Intangible Assets
Schedule of Finite-Lived Intangible Assets [Table Text Block]
Schedule of Finite-Lived Intangible Assets, Future Amortization Expense
Schedule of Finite-Lived Intangible Assets, Future Amortization Expense [Table Text Block]
Disclosure Change In Carrying Value Of Goodwill [Abstract]
Disclosure - Change in Carrying Value of Goodwill [Abstract]
Schedule of Goodwill [Table]
Schedule of Goodwill [Table]
Business Segments [Axis]
Segments [Axis]
Segment [Domain]
Segments [Domain]
Clear Aligner
Clear Aligner [Member]
Clear Aligner [Member]
Goodwill [Line Items]
Goodwill [Line Items]
Goodwill [Roll Forward]
Goodwill [Roll Forward]
Balance as of December 31, 2016
Goodwill
Goodwill from distributor acquisitions
Goodwill, Acquired During Period
Adjustments
Goodwill, Translation and Purchase Accounting Adjustments
Balance as of September 30, 2017
Investments, Debt and Equity Securities [Abstract]
One year or less
Available-for-sale Securities, Current
Due in greater than one year
Available-for-sale Securities, Noncurrent
Total available for sale short-term and long-term marketable securities
Available-for-sale Securities
Statement of Comprehensive Income [Abstract]
Net income
Net change in foreign currency translation adjustment
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax
Change in unrealized gains (losses) on investments, net of tax
Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax
Other comprehensive income (loss)
Other Comprehensive Income (Loss), Net of Tax
Comprehensive income
Comprehensive Income (Loss), Net of Tax, Attributable to Parent
Net income
Weighted-average common shares outstanding, basic
Dilutive effect of potential common stock
Weighted Average Number Diluted Shares Outstanding Adjustment
Total shares, diluted
Net income per share, basic
Net income per share, diluted
Goodwill and Intangible Assets
Goodwill and Intangible Assets Disclosure [Text Block]
Legal Proceedings [Abstract]
Legal Proceedings [Abstract]
Legal Proceedings
Legal Proceedings [Text Block]
Legal Proceedings [Text Block]
Disclosure Stock Based Compensation Expense Related To All Stock Based Awards And Employee Stock Purchases [Abstract]
Disclosure - Stock-Based Compensation Expense Related to All Stock-Based Awards and Employee Stock Purchases [Abstract]
Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Table]
Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Table]
Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs, by Report Line [Axis]
Income Statement Location [Axis]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs, Report Line [Domain]
Income Statement Location [Domain]
Cost of net revenues
Cost of Sales [Member]
Selling, general and administrative
Selling and Marketing Expense [Member]
Research and development
Research and Development Expense [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation expense
Allocated Share-based Compensation Expense
Equity Method Investments and Joint Ventures [Abstract]
Equity Method Investments
Equity Method Investments and Joint Ventures Disclosure [Text Block]
Statement [Table]
Statement [Table]
Statement [Line Items]
Statement [Line Items]
Accounting for Income Taxes
Income Tax Disclosure [Text Block]
Goodwill and Intangible Asset Impairment [Abstract]
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill impairment
Goodwill, Impairment Loss
Amortization
Amortization of Intangible Assets
Common Stock Repurchase
Share Repurchase Program Disclosure [Text Block]
Share Repurchase Program Disclosure
Segments and Geographical Information
Segment Reporting Disclosure [Text Block]
Disclosure Credit Facilities Additional Information [Abstract]
Disclosure - Credit Facilities - Additional Information [Abstract]
Line of Credit Facility [Table]
Line of Credit Facility [Table]
Credit Facility [Axis]
Credit Facility [Axis]
Credit Facility [Domain]
Credit Facility [Domain]
Revolving Credit Facility [Member]
Revolving Credit Facility [Member]
Letter of Credit [Member]
Letter of Credit [Member]
Lender Name [Axis]
Lender Name [Axis]
Line of Credit Facility, Lender [Domain]
Line of Credit Facility, Lender [Domain]
Wells Fargo [Member]
Wells Fargo [Member]
Wells Fargo [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility [Line Items]
Line of credit, available borrowings
Line of Credit Facility, Maximum Borrowing Capacity
Debt Instrument, Basis Spread on Variable Rate
Debt Instrument, Basis Spread on Variable Rate
Outstanding
Long-term Line of Credit
Schedule of Inventories
Schedule of Inventory, Current [Table Text Block]
Schedule of Accrued Liabilities
Schedule of Accrued Liabilities [Table Text Block]
Warranty Accrual
Schedule of Product Warranty Liability [Table Text Block]
Disclosure Stockbased Compensation Additional Information [Abstract]
Disclosure - Stock-based Compensation - Additional Information [Abstract]
Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table]
Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table]
Income Statement Location [Axis]
Income Statement Location [Domain]
Selling, general and administrative
Research and Development Expense [Member]
Award Type [Axis]
Award Type [Axis]
Award Type [Domain]
Equity Award [Domain]
Employee Stock Purchase Plan 2010
Employee Stock Purchase Plan 2010 [Member]
Employee Stock Purchase Plan, 2010 [Member]
Restricted Stock Units (RSUs)
Restricted Stock Units (RSUs) [Member]
Market Performance Based Restricted Stock Units
Market Performance Based Restricted Stock Units [Member]
Market Performance Based Restricted Stock Units [Member]
Employee Stock Purchase Plan
Employee Stock Purchase Plan [Member]
Employee Stock Purchase Plan [Member]
Schedule of Share-based Compensation Arrangement by Share-based Payment Award [Axis]
Schedule Of Share Based Compensation Arrangement By Share Based Payment Award [Axis]
Schedule of Share-based Compensation Arrangement by Share-based Payment Award [Axis]
Share-based Compensation Arrangements by Share-based Payment Award [Domain]
Share Based Compensation Arrangements By Share Based Payment Award [Domain]
Share-based Compensation Arrangements by Share-based Payment Award [Domain]
Incentive Plan 2005
Stock Incentive Plan 2005 [Member]
2005 Stock Incentive Plan [Member]
Minimum
Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated Share-based Compensation Expense
Shares reserved for issuance
Common Stock, Capital Shares Reserved for Future Issuance
Number of shares available for issuance
Common Stock, Capital Shares Reserved For Future Issuance, Shares Available
Common Stock, Capital Shares Reserved For Future Issuance, Shares Available
Total unamortized compensation cost
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized
Weighted average period of total unamortized cost (in years)
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition
Vesting period of granted market-performance based restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period
Percentage of market-performance based restricted stock units eligible to vest over the vesting period
Percentage Of Market Performance Based Restricted Stock Units During Vesting Period
Maximum percentage of market-performance based restricted stock units during vesting period.
Maximum number of shares available
Employee Stock Purchase Plan Number Of Shares Available For Issuance
Employee Stock Purchase Plan, Number Of Shares Available for Issuance
Number of shares remaining
Share Based Compensation Arrangement By Share Based Payment Award Shares Remaining Available For Issuance
Share Based Compensation Arrangement By Share Based Payment Award Shares Remaining Available For Issuance
Disclosure Net Revenues By Geographic Area [Abstract]
Disclosure - Net Revenues by Geographic Area [Abstract]
Disclosure Accrued Liabilities [Abstract]
Disclosure - Accrued Liabilities [Abstract]
Accrued payroll and benefits
Employee-related Liabilities, Current
Accrued expenses
Accrued Sales And Marketing Current
Accrued Sales and Marketing, Current
Accrued income taxes
Accrued Income Taxes, Current
Accrued sales rebate
Accrued Marketing Costs, Current
Accrued sales tax and value added tax
Sales and Excise Tax Payable, Current
Accrued professional fees
Accrued Professional Fees, Current
Accrued warranty
Standard Product Warranty Accrual, Current
Other accrued liabilities
Other Accrued Liabilities, Current
Total accrued liabilities
Schedule of Equity Method Investments [Table]
Schedule of Equity Method Investments [Table]
Investment, Name [Axis]
Investment, Name [Axis]
Investment, Name [Domain]
Investment, Name [Domain]
Schedule of Equity Method Investments [Line Items]
Schedule of Equity Method Investments [Line Items]
Ownership
Equity Method Investment, Ownership Percentage
Payments to acquire
Payments to Acquire Equity Method Investments
Additional ownership acquired
Equity Method Investment, Ownership Acquired
Equity Method Investment, Ownership Acquired
Equity method investments
Equity Method Investments
Due from related parties
Due from Related Parties
Loan receivable
Loans and Leases Receivable, Related Parties
Net Income Per Share
Earnings Per Share [Text Block]
Statement of Cash Flows [Abstract]
CASH FLOWS FROM OPERATING ACTIVITIES:
Net Cash Provided by (Used in) Operating Activities [Abstract]
Adjustments to reconcile net income to net cash provided by operating activities:
Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract]
Deferred taxes
Deferred Income Tax Expense (Benefit)
Depreciation and amortization
Depreciation, Depletion and Amortization
Stock-based compensation
Share-based Compensation
Net tax benefits from stock-based awards
Tax Benefits Shortfalls From Stock Based Awards
Tax Benefits Shortfalls From Stock Based Awards
Excess tax benefit from share-based payment arrangements
Excess Tax Benefit from Share-based Compensation, Operating Activities
Equity in losses of investee
Other non-cash operating activities
Other Noncash Income (Expense)
Changes in assets and liabilities, net of effects of acquisitions:
Increase (Decrease) in Operating Capital [Abstract]
Accounts receivable
Increase (Decrease) in Accounts Receivable
Inventories
Increase (Decrease) in Inventories
Prepaid expenses and other assets
Increase (Decrease) in Prepaid Expense and Other Assets
Accounts payable
Increase (Decrease) in Accounts Payable
Accrued and other long-term liabilities
Increase (Decrease) in Accrued Liabilities and Other Operating Liabilities
Deferred revenues
Increase (Decrease) in Deferred Revenue
Net cash provided by operating activities
Net Cash Provided by (Used in) Operating Activities
CASH FLOWS FROM INVESTING ACTIVITIES:
Net Cash Provided by (Used in) Investing Activities [Abstract]
Acquisitions, net of cash acquired
Payments to Acquire Businesses, Net of Cash Acquired
Purchase of property, plant and equipment
Payments to Acquire Property, Plant, and Equipment
Purchase of marketable securities
Payments to Acquire Available-for-sale Securities
Proceeds from maturities of marketable securities
Proceeds from Sale and Maturity of Available-for-sale Securities
Purchase of equity method investments
Proceeds from sales of marketable securities
Proceeds from Sale of Available-for-sale Securities
Loan advances to equity investee
Payments to Acquire Loans Receivable
Loan repayment from equity investee
Proceeds from Collection of Loans Receivable
Other investing activities
Payments for (Proceeds from) Other Investing Activities
Net cash provided by (used in) investing activities
Net Cash Provided by (Used in) Investing Activities
CASH FLOWS FROM FINANCING ACTIVITIES:
Net Cash Provided by (Used in) Financing Activities [Abstract]
Proceeds from issuance of common stock
Proceeds from Issuance of Common Stock
Common stock repurchases
Payments for Repurchase of Common Stock
Excess tax benefit from share-based payment arrangements
Excess Tax Benefit from Share-based Compensation, Financing Activities
Employees’ taxes paid upon the vesting of restricted stock units
Payments Related to Tax Withholding for Share-based Compensation
Net cash used in financing activities
Net Cash Provided by (Used in) Financing Activities
Effect of foreign exchange rate changes on cash and cash equivalents
Effect of Exchange Rate on Cash and Cash Equivalents
Net increase (decrease) in cash and cash equivalents
Cash and Cash Equivalents, Period Increase (Decrease)
Cash and cash equivalents, beginning of the period
Cash and Cash Equivalents, at Carrying Value
Cash and cash equivalents, end of the period
SUPPLEMENTAL CASH FLOW INFORMATION:
Supplemental Cash Flow Information [Abstract]
Accounts payable or accrued liabilities related to property, plant and equipment
Capital Expenditures Incurred but Not yet Paid
Disclosure Summary Of Financial Assets Measured At Fair Value On Recurring Basis [Abstract]
Disclosure - Summary of Financial Assets Measured at Fair Value on Recurring Basis [Abstract]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Table]
Fair Value Assets And Liabilities Measured On Recurring Basis [Table]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Table]
Fair Value by Measurement Frequency [Axis]
Measurement Frequency [Axis]
Fair Value, Measurement Frequency [Domain]
Fair Value, Measurement Frequency [Domain]
Fair Value, Measurements, Recurring [Member]
Fair Value, Measurements, Recurring [Member]
Fair Value, Hierarchy [Axis]
Fair Value, Hierarchy [Axis]
Fair Value Hierarchy [Domain]
Fair Value Hierarchy [Domain]
Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Inputs, Level 1 [Member]
Significant Other Observable Inputs (Level 2)
Fair Value, Inputs, Level 2 [Member]
Significant Other Observable Inputs (Level 3)
Fair Value, Inputs, Level 3 [Member]
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Axis]
Investment Type [Axis]
Schedule of Fair Value of Separate Accounts by Major Category of Investment, Category [Domain]
Investments [Domain]
Cash Equivalents
Cash Equivalents [Member]
Short-term Investments
Short-term Investments [Member]
Long-term Investments
Long Term Investments [Member]
Long Term Investments [Member]
Restricted Cash and Cash Equivalents, Cash and Cash Equivalents [Axis]
Restricted Cash and Cash Equivalents [Axis]
Restricted Cash and Cash Equivalents, Cash and Cash Equivalents [Domain]
Cash and Cash Equivalents [Domain]
Money market funds
Money Market Funds [Member]
Commercial paper
Commercial Paper [Member]
U.S. government treasury bonds
US Treasury and Government [Member]
Municipal securities
US States and Political Subdivisions Debt Securities [Member]
Corporate bonds
Corporate Bond Securities [Member]
Schedule of Available-for-sale Securities, Major Types of Debt and Equity Securities [Axis]
Major Types of Debt and Equity Securities [Axis]
Major Types of Debt and Equity Securities [Domain]
Major Types of Debt and Equity Securities [Domain]
Municipal securities
Municipal Securities [Member]
Municipal Securities [Member]
U.S. government agency bonds
Agency Securities [Member]
Certificates of deposit
Certificates of Deposit [Member]
Asset-backed securities
Asset-backed Securities [Member]
Prepaid expenses and other current assets
Prepaid Expenses and Other Current Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Cash equivalents
Cash and Cash Equivalents, Fair Value Disclosure
Investments
Other assets
Other Assets, Fair Value Disclosure
Long-term notes receivable
Notes Receivable, Fair Value Disclosure
Assets, Fair Value Disclosure
Assets, Fair Value Disclosure
Balance Sheet Components
Supplemental Balance Sheet Disclosures [Text Block]
Disclosure Intangible Assets As Direct Result From Cadent Acquisition [Abstract]
Disclosure - Intangible Assets as Direct Result from Cadent Acquisition [Abstract]
Schedule of Finite-Lived Intangible Assets by Major Class [Table]
Schedule of Finite-Lived Intangible Assets [Table]
Acquired Finite-Lived Intangible Assets by Major Class [Axis]
Finite-Lived Intangible Assets by Major Class [Axis]
Finite-Lived Intangible Assets, Major Class Name [Domain]
Finite-Lived Intangible Assets, Major Class Name [Domain]
Trademarks
Trademarks [Member]
Existing technology
Existing Technology [Member]
Existing Technology [Member]
Customer relationships
Customer Relationships [Member]
Reacquired rights
Distribution Rights [Member]
Patents
Patents [Member]
Other
Other Intangible Assets [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets [Line Items]
Weighted Average Amortization Period (in years)
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life
Gross Carrying Amount, beginning balance
Finite-Lived Intangible Assets, Gross
Accumulated Amortization
Finite Lived Intangible Assets Accumulated Amortization Period Increase Decrease
Finite-Lived Intangible Assets, Accumulated Amortization, Period Increase (Decrease)
Accumulated Impairment Loss
Finite-Lived Intangible Assets, Accumulated Impairment Loss
Finite-Lived Intangible Assets, Accumulated Impairment Loss
Disclosure Warranty Accrual Activity [Abstract]
Disclosure - Warranty Accrual Activity [Abstract]
Movement in Standard Product Warranty Accrual [Roll Forward]
Movement in Standard Product Warranty Accrual [Roll Forward]
Balance at beginning of period
Standard Product Warranty Accrual
Charged to cost of revenues
Standard Product Warranty Accrual, Increase for Warranties Issued
Actual warranty expenditures
Standard Product Warranty Accrual, Decrease for Payments
Balance at end of period
Disclosure Activity Under Stock Option Plans [Abstract]
Disclosure - Activity Under Stock Option Plans [Abstract]
Number of Shares Underlying Stock Options
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Outstanding as of December 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number
Exercised
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period
Cancelled or expired
Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures and Expirations in Period
Outstanding as of September 30, 2017
Vested and expected to vest at September 30, 2017
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Number
Exercisable at September 30, 2017
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Number
Weighted Average Exercise Price per Share
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract]
Outstanding as of December 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price
Exercised
Share-based Compensation Arrangements by Share-based Payment Award, Options, Exercises in Period, Weighted Average Exercise Price
Cancelled or expired
Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures and Expirations in Period, Weighted Average Exercise Price
Outstanding as of September 30, 2017
Vested and expected to vest at September 30, 2017
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Weighted Average Exercise Price
Exercisable at September 30, 2017
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Exercise Price
Weighted Average Remaining Contractual Term
Share Based Compensation Arrangement By Share Based Payment Award Options Weighted Average Remaining Contractual Term [Abstract]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Weighted Average Remaining Contractual Term [Abstract]
Outstanding as of September 30, 2017
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term
Vested and expected to vest at September 30, 2017
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Weighted Average Remaining Contractual Term
Exercisable at September 30, 2017
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Remaining Contractual Term
Aggregate Intrinsic Value
Share Based Compensation Arrangement By Share Based Payment Award Options Aggregate Intrinsic Value [Abstract]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Aggregate Intrinsic Value [Abstract]
Outstanding as of September 30, 2017
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Intrinsic Value
Vested and expected to vest at September 30, 2017
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Aggregate Intrinsic Value
Exercisable at September 30, 2017
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Intrinsic Value
Schedule of Revenue from External Customers and Long-Lived Assets, by Geographical Areas
Schedule of Revenue from External Customers and Long-Lived Assets, by Geographical Areas [Table Text Block]
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Expected term (in years)
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Term
Expected volatility
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate
Risk-free interest rate
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate
Expected dividends
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate
Weighted average fair value at grant date (USD per Share)
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value
Business Combinations [Abstract]
Business Combinations
Business Combination Disclosure [Text Block]
Summary of Significant Accounting Policies
Significant Accounting Policies [Text Block]
Disclosure Short Term And Long Term Marketable Securities [Abstract]
Disclosure - Short-Term and Long-Term Marketable Securities [Abstract]
Schedule of Available-for-sale Securities [Table]
Schedule of Available-for-sale Securities [Table]
Corporate bonds
Corporate Bonds [Member]
Corporate Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost
Available-for-sale Securities, Amortized Cost Basis
Gross Unrealized Gains
Available For Sale Securities Gross Unrealized Gain In Investments
Available For Sale Securities Gross Unrealized Gain In Investments
Gross Unrealized Losses
Available For Sale Securities Gross Unrealized Loss In Investments
Available For Sale Securities Gross Unrealized Loss In Investments
Schedule of Business Acquisitions, by Acquisition [Table]
Schedule of Business Acquisitions, by Acquisition [Table]
Certain Distributors
Certain Distributors [Member]
Certain Distributors [Member]
Business Acquisition [Line Items]
Business Acquisition [Line Items]
Cash consideration
Payments to Acquire Businesses, Gross
Net tangible liabilities
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities
Intangibles acquired
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill
Goodwill and intangible assets, net
Disclosure Segment Information [Abstract]
Disclosure - Segment Information [Abstract]
Operating segments
Other Segments [Member]
Clear Aligner
Scanner
Scanners And Services [Member]
Scanners and Services [Member]
Unallocated corporate expenses
Corporate and Other [Member]
Revenue
Gross profit
Income from operations
Depreciation and amortization
Interest and other income (expense), net
Statement of Financial Position [Abstract]
Accounts receivable, allowance for doubtful accounts and returns
Allowance For Doubtful Accounts Receivable And Sales Returns Current
Allowance For Doubtful Accounts Receivable And Sales Returns Current
Preferred stock, par value (in usd per share)
Preferred Stock, Par or Stated Value Per Share
Preferred stock, shares authorized
Preferred Stock, Shares Authorized
Preferred stock, shares issued
Preferred Stock, Shares Issued
Common stock, par value (in usd per share)
Common Stock, Par or Stated Value Per Share
Common stock, shares authorized
Common Stock, Shares Authorized
Common stock, shares issued
Common Stock, Shares, Issued
Common stock, shares outstanding
Common Stock, Shares, Outstanding
Major Types of Debt and Equity Securities [Axis]
Fair value
Maturity Period Used To Classify Investments
Maturity Period Used To Classify Investments
Maturity Period Used to Classify Investments
Fair Value Disclosures [Abstract]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance as of December 31, 2016
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value
Additional notes receivable issued
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Issuances
Accrued interest receivable
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Accrual
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Accrual
Change in fair value recognized in earnings
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings
Balance as of September 30, 2017
Credit Facilities
Debt Disclosure [Text Block]
ASSETS
Assets [Abstract]
Current assets:
Assets, Current [Abstract]
Cash and cash equivalents
Marketable securities, short-term
Available-for-sale Securities, Debt Securities, Current
Accounts receivable, net of allowance for doubtful accounts and returns of $5,843 and $4,310, respectively
Accounts Receivable, Net, Current
Inventories
Prepaid expenses and other current assets
Prepaid Expense and Other Assets, Current
Total current assets
Assets, Current
Marketable securities, long-term
Available-for-sale Securities, Debt Securities, Noncurrent
Property, plant and equipment, net
Property, Plant and Equipment, Net
Goodwill and intangible assets, net
Deferred tax assets
Deferred Tax Assets, Net of Valuation Allowance, Noncurrent
Other assets
Other Assets, Noncurrent
Total assets
Assets
LIABILITIES AND STOCKHOLDERS' EQUITY
Liabilities and Equity [Abstract]
Current liabilities:
Liabilities, Current [Abstract]
Accounts payable
Accounts Payable, Current
Deferred revenues
Deferred Revenue, Current
Total current liabilities
Liabilities, Current
Income tax payable
Taxes Payable
Other long-term liabilities
Other Liabilities, Noncurrent
Total liabilities
Liabilities
Commitments and contingencies (Note 8 and 9)
Commitments and Contingencies
Stockholders' equity:
Stockholders' Equity Attributable to Parent [Abstract]
Preferred stock, $0.0001 par value (5,000 shares authorized; none issued)
Preferred Stock, Value, Issued
Common stock, $0.0001 par value (200,000 shares authorized; 80,176 and 79,553 issued and outstanding, respectively)
Common Stock, Value, Issued
Additional paid-in capital
Additional Paid in Capital
Accumulated other comprehensive income (loss), net
Accumulated Other Comprehensive Income (Loss), Net of Tax
Retained earnings
Retained Earnings (Accumulated Deficit)
Total stockholders’ equity
Stockholders' Equity Attributable to Parent
Total liabilities and stockholders’ equity
Liabilities and Equity
Disclosure Common Stock Repurchase Program Additional Information [Abstract]
Disclosure - Common Stock Repurchase Program - Additional Information [Abstract]
Share Repurchases [Table]
Share Repurchases [Table]
Share Repurchases [Table]
Share Repurchase Program [Axis]
Share Repurchase Program [Axis]
Share Repurchase Program [Domain]
Share Repurchase Program [Domain]
April 2014 Repurchase Program
April 2014 Stock Repurchase Program [Member]
April 2014 Stock Repurchase Program [Member]
April 2016 Repurchase Program
April 2016 Repurchase [Member]
April 2016 Repurchase [Member]
2017 ASR
2017 Stock Repurchase Program [Member]
2017 Stock Repurchase Program [Member]
Share Repurchases [Line Items]
Share Repurchases [Line Items]
Share Repurchases [Line Items]
Repurchase of common stock, common stock authorized
Stock Repurchase Program, Authorized Amount
Stock repurchase program, period
Stock Repurchase Program, Period in Force
Accelerated share repurchase (shares)
Stock Repurchased and Retired During Period, Shares
Market price ($ per share)
Average Share Price
Average Share Price
Repurchased
Stock Repurchased and Retired During Period, Value
Price ($ per share)
Accelerated Share Repurchases, Final Price Paid Per Share
Amount remaining in repurchase plan
Stock Repurchase Program, Remaining Authorized Repurchase Amount
Schedule of Future Lease Payments
Schedule of Future Minimum Rental Payments for Operating Leases [Table Text Block]
Disclosure Accounting For Income Taxes Additional Information [Abstract]
Disclosure - Accounting for Income Taxes - Additional Information [Abstract]
Income Taxes [Table]
Income Taxes [Table]
Income Taxes [Table]
Income Tax Authority [Axis]
Income Tax Authority [Axis]
Income Tax Authority [Domain]
Income Tax Authority [Domain]
Foreign Tax Authority
Foreign Tax Authority [Member]
Income Taxes [Line Items]
Income Taxes [Line Items]
Income Taxes [Line Items]
Effective income tax rate, continuing operations
Effective Income Tax Rate Reconciliation, Percent
Statutory federal income tax rate
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent
Unrecognized tax benefits
Unrecognized Tax Benefits
Accrued penalties and interest
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued
Foreign income tax rate
Effective Income Tax Reconciliation, at Foreign Income Tax Rate
Effective Income Tax Reconciliation, at Foreign Income Tax Rate
Tax Holiday effect
Effective Income Tax Rate Reconciliation, Tax Holiday, Amount
Tax holiday effect on diluted earnings per share
Effective Income Tax Rate Reconciliation, Tax Holiday, Effect on Diluted Earnings Per Share
Effective Income Tax Rate Reconciliation, Tax Holiday, Effect on Diluted Earnings Per Share
Disclosure Summary Of M S U Performance [Abstract]
Disclosure - Summary of MSU Performance [Abstract]
Number of Shares Underlying MSUs
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Nonvested as of December 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number
Granted
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period
Vested and released
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period
Forfeited
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period
Nonvested as of September 30, 2017
Weighted Average Grant Date Fair Value
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Nonvested as of December 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value
Granted
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value
Vested and released
Sharebased Compensation Arrangement By Sharebased Payment Award Equity Instruments Other Than Options Vested And Released In Period Weighted Average Grant Date Fair Value
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other Than Options Vested And Released In Period Weighted Average Grant Date Fair Value
Forfeited
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value
Nonvested as of September 30, 2017
Weighted Average Remaining Vesting Period
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]
Nonvested as of September 30, 2017
Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Outstanding Weighted Average Remaining Contractual Term 1
Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Outstanding Weighted Average Remaining Contractual Term 1
Aggregate Intrinsic Value
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Aggregate Intrinsic Value [Abstract]
Nonvested as of September 30, 2017
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Aggregate Intrinsic Value, Outstanding
Schedule Of Earnings Per Share Basic And Diluted
Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]
Disclosure Summary Of Nonvested Shares [Abstract]
Disclosure - Summary of Nonvested Shares [Abstract]
Number of Shares Underlying RSUs
Weighted Remaining Vesting Period
Basis of presentation
Basis of Accounting, Policy [Policy Text Block]
Out of period adjustment
Out Of Period Adjustment [Policy Text Block]
Out Of Period Adjustment [Policy Text Block]
Use of estimates
Use of Estimates, Policy [Policy Text Block]
Recent Accounting Pronouncements
Recent Accounting Pronouncements [Policy Text Block]
Recent accounting pronouncements , Policy [Text Block]