Cash, Financial Institutions Used

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- Definition

Lease Term

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No definition available.

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- Definition

Maturity Period Used to Classify Investments

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- Definition

Medical Device Excise Tax Expense (Benefit)

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- Definition

Standard Product Warranty Time Period

+ References

No definition available.

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- Definition

Amount charged to advertising expense for the period, which are expenses incurred with the objective of increasing revenue for a specified brand, product or product line.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 720

-SubTopic 35

-Section 50

-Paragraph 1

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- Definition

Additions made to capitalized computer software costs during the period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 30

-Section 50

-Paragraph 1

-Subparagraph (a)

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- Definition

Useful life of finite-lived intangible assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

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- Definition

Amount before tax of foreign currency transaction realized gain (loss) recognized in the income statement.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 830

-SubTopic 20

-Section 45

-Paragraph 1

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-SubTopic 20

-Section 50

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-Topic 830

-SubTopic 20

-Section 45

-Paragraph 2

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- Definition

Number of operating segments. An operating segment is a component of an enterprise: (a) that engages in business activities from which it may earn revenues and incur expenses (including revenues and expenses relating to transactions with other components of the same enterprise), (b) whose operating results are regularly reviewed by the enterprise's chief operating decision maker to make decisions about resources to be allocated to the segment and assess its performance, and (c) for which discrete financial information is available. An operating segment may engage in business activities for which it has yet to earn revenues, for example, start-up operations may be operating segments before earning revenues.

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- Definition

Useful life of long lived, physical assets used in the normal conduct of business and not intended for resale, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Examples include, but not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment.

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No definition available.

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- Definition

The carrying amounts of cash and cash equivalent items which are restricted as to withdrawal or usage. Restrictions may include legally restricted deposits held as compensating balances against short-term borrowing arrangements, contracts entered into with others, or entity statements of intention with regard to particular deposits; however, time deposits and short-term certificates of deposit are not generally included in legally restricted deposits. Excludes compensating balance arrangements that are not agreements which legally restrict the use of cash amounts shown on the balance sheet. For a classified balance sheet represents the current portion only (the noncurrent portion has a separate concept); there is a separate and distinct element for unclassified presentations.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 1

-Article 5

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-Publisher FASB

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-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.1)

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- Definition

Amount of undistributed earnings of foreign subsidiaries intended to be permanently reinvested outside the country of domicile.

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 740

-SubTopic 30

-Section 50

-Paragraph 2

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Summary of Significant Accounting Policies - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014 financial_institution segment	Dec. 31, 2013	Dec. 31, 2012
Significant Accounting Policies [Line Items]
Number of operating segments	2us-gaap_NumberOfOperatingSegments
Restricted cash	$ 3.8
Original maturity of highly liquid investments included in Cash and cash equivalents	2 years
Foreign currency net loss	3.8
Number of financial instutions used	2algn_CashFinancialInstitutionsUsed
Scanners, Warranty period	1 year
Advertising cost	26.9us-gaap_AdvertisingExpense	26.0us-gaap_AdvertisingExpense	23.6us-gaap_AdvertisingExpense
Lease term	9 years
Undistributed earnings of foreign subsidiaries	260.9
Medical device tax expense	6.8
Building
Significant Accounting Policies [Line Items]
Property plant and equipment estimated useful lives	20 years
Software Development
Significant Accounting Policies [Line Items]
Property plant and equipment estimated useful lives	10 years
Capitalized computer software development expenses during period	2.6
Minimum
Significant Accounting Policies [Line Items]
Property plant and equipment estimated useful lives	3 years
Estimated useful lives of intangibles	1 year
Maximum
Significant Accounting Policies [Line Items]
Original maturity of highly liquid investments included in Cash and cash equivalents	3 months
Property plant and equipment estimated useful lives	10 years
Estimated useful lives of intangibles	15 years
Noncurrent Assets
Significant Accounting Policies [Line Items]
Restricted cash		4.0
Other Noncurrent Assets
Significant Accounting Policies [Line Items]
Restricted cash	3.6	4.0
Prepaid Expenses and Other Current Assets
Significant Accounting Policies [Line Items]
Restricted cash		1.6
Other Current Assets
Significant Accounting Policies [Line Items]
Restricted cash	$ 0.2