Segments and Geographical Information - Segment Information (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2020	Mar. 31, 2019
Segment Reporting Information [Line Items]
Net revenues	$ 550,963	$ 548,971
Gross profit	394,356	402,096
Income from operations	69,918	87,701
Interest income	1,986	2,633
Impairments and other charges	0	29,782
Depreciation and amortization	20,738	18,316
Other income (expense), net	(18,549)	(5,746)
Net income before provision for income taxes and equity in losses of investee	53,355	84,588
Operating Segments
Segment Reporting Information [Line Items]
Income from operations	180,777	186,900
Clear Aligner
Segment Reporting Information [Line Items]
Net revenues	481,611	469,205
Gross profit	351,492	351,358
Income from operations	166,388	158,641
Impairments and other charges	0	29,782
Depreciation and amortization	10,121	9,090
Scanner
Segment Reporting Information [Line Items]
Net revenues	69,352	79,766
Gross profit	42,864	50,738
Income from operations	14,389	28,259
Depreciation and amortization	1,785	1,508
Corporate, Non-Segment
Segment Reporting Information [Line Items]
Income from operations	(110,859)	(99,199)
Unallocated corporate expenses
Segment Reporting Information [Line Items]
Income from operations	(110,859)	(99,199)
Depreciation and amortization	$ 8,832	$ 7,718

The aggregate expense recognized in the current period that allocates the cost of tangible assets, intangible assets, or depleting assets to periods that benefit from use of the assets.

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