Segments and Geographical Information - Segment Information (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Segment Reporting Information [Line Items]
Net revenues	$ 352,314	$ 600,697	$ 903,277	$ 1,149,668
Gross profit	224,328	432,289	618,684	834,385
Income (loss) from operations	(73,000)	176,490	(3,082)	264,191
Depreciation and amortization	23,545	19,172	44,283	37,488
Impairments and other charges	0	0	0	29,782
Litigation settlement gain	0	(51,000)	0	(51,000)
Interest income	473	3,465	2,459	6,098
Other income (expense), net	(966)	13,892	(19,515)	8,146
Net income before provision for income taxes and equity in losses of investee	(73,493)	193,847	(20,138)	278,435
Operating Segments
Segment Reporting Information [Line Items]
Income (loss) from operations	41,809	283,296	222,586	470,196
Clear Aligner
Segment Reporting Information [Line Items]
Net revenues	298,341	496,702	779,952	965,907
Gross profit	192,366	366,142	543,858	717,500
Income (loss) from operations	38,916	244,029	205,304	402,670
Depreciation and amortization	9,697	9,455	19,818	18,545
Impairments and other charges	0	0	0	29,782
Litigation settlement gain	0	(51,000)	0	(51,000)
Systems and Services
Segment Reporting Information [Line Items]
Net revenues	53,973	103,995	123,325	183,761
Gross profit	31,962	66,147	74,826	116,885
Income (loss) from operations	2,893	39,267	17,282	67,526
Depreciation and amortization	5,005	1,854	6,790	3,362
Unallocated corporate expenses
Segment Reporting Information [Line Items]
Income (loss) from operations	(114,809)	(106,806)	(225,668)	(206,005)
Depreciation and amortization	$ 8,843	$ 7,863	$ 17,675	$ 15,581

Amount of write-down of assets recognized in the income statement. Includes, but is not limited to, losses from tangible assets, intangible assets and goodwill.

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