Goodwill and Intangible Assets - Change in the Carrying Value of Goodwill (Detail) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2021	Dec. 31, 2020
Goodwill [Roll Forward]
Beginning Balance	$ 444,817	$ 63,924
Additions from acquisition	3,646	340,181
Foreign currency translation adjustments	(29,916)	40,712
Ending Balance	418,547	444,817
Clear Aligner
Goodwill [Roll Forward]
Beginning Balance	112,691	63,924
Additions from acquisition	3,646	43,500
Foreign currency translation adjustments	(4,129)	5,267
Ending Balance	112,208	112,691
Systems and Services
Goodwill [Roll Forward]
Beginning Balance	332,126	0
Additions from acquisition	0	296,681
Foreign currency translation adjustments	(25,787)	35,445
Ending Balance	$ 306,339	$ 332,126

Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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Amount of increase in asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized resulting from a business combination.

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Amount of foreign currency translation gain (loss) which increases (decreases) an asset representing future economic benefits from other assets acquired in a business combination that are not individually identified and separately recognized.

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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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