Unaudited Consolidated Statements of Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock Class A Common Stock	Common Stock Class B Convertible Common Stock	Common Stock Class C Common Stock	Additional Paid-in-Capital	Retained Earnings	Accumulated Other Comprehensive Income (Loss)
Beginning balance (shares) at Dec. 31, 2018		187,710	34,450	226,422
Beginning balance at Dec. 31, 2018	$ 2,016,871	$ 62	$ 11	$ 75	$ 916,628	$ 1,139,082	$ (38,987)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of stock options (shares)		315		237
Exercise of stock options	1,376				1,376
Shares withheld in consideration of employee tax obligations relative to stock-based compensation arrangements (shares)		(15)		(158)
Shares withheld in consideration of employee tax obligations relative to stock-based compensation arrangements	(3,081)					(3,081)
Issuance of common stock, net of forfeitures (shares)		134		2,152
Issuance of common stock, net of forfeitures	2,860			$ 1	2,859
Stock-based compensation expense	25,625				25,625
Comprehensive income (loss)	4,623					5,128	(505)
Ending balance (shares) at Jun. 30, 2019		188,144	34,450	228,653
Ending balance at Jun. 30, 2019	2,048,274	$ 62	$ 11	$ 76	946,488	1,141,129	(39,492)
Beginning balance (shares) at Mar. 31, 2019		187,980	34,450	228,489
Beginning balance at Mar. 31, 2019	2,049,807	$ 62	$ 11	$ 76	931,352	1,158,482	(40,176)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of stock options (shares)		161		59
Exercise of stock options	529				529
Shares withheld in consideration of employee tax obligations relative to stock-based compensation arrangements (shares)		(5)		(6)
Shares withheld in consideration of employee tax obligations relative to stock-based compensation arrangements	(4)					(4)
Issuance of common stock, net of forfeitures (shares)		8		111
Issuance of common stock, net of forfeitures	1,473			$ 0	1,473
Stock-based compensation expense	13,134				13,134
Comprehensive income (loss)	(16,665)					(17,349)	684
Ending balance (shares) at Jun. 30, 2019		188,144	34,450	228,653
Ending balance at Jun. 30, 2019	2,048,274	$ 62	$ 11	$ 76	946,488	1,141,129	(39,492)
Beginning balance (shares) at Dec. 31, 2019		188,290	34,450	229,028
Beginning balance at Dec. 31, 2019	2,150,087	$ 62	$ 11	$ 76	973,717	1,226,986	(50,765)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of stock options (shares)		145		133
Exercise of stock options	499				499
Shares withheld in consideration of employee tax obligations relative to stock-based compensation arrangements (shares)		(1)		(176)
Shares withheld in consideration of employee tax obligations relative to stock-based compensation arrangements	(3,660)					(3,660)
Issuance of common stock, net of forfeitures (shares)		27		2,369
Issuance of common stock, net of forfeitures	2,360			$ 1	2,359
Stock-based compensation expense	23,257				23,257
Equity Component value of convertible note issuance, net	44,223				44,223
Comprehensive income (loss)	(793,352)					(772,576)	(20,776)
Ending balance (shares) at Jun. 30, 2020		188,461	34,450	231,354
Ending balance at Jun. 30, 2020	1,423,414	$ 62	$ 11	$ 77	1,044,055	450,750	(71,541)
Beginning balance (shares) at Mar. 31, 2020		188,451	34,450	231,150
Beginning balance at Mar. 31, 2020	1,550,180	$ 62	$ 11	$ 77	985,831	634,452	(70,253)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of stock options (shares)		2		2
Exercise of stock options	14				14
Shares withheld in consideration of employee tax obligations relative to stock-based compensation arrangements (shares)		0		0
Shares withheld in consideration of employee tax obligations relative to stock-based compensation arrangements	(807)					(807)
Issuance of common stock, net of forfeitures (shares)		8		202
Issuance of common stock, net of forfeitures	1,195			$ 0	1,195
Stock-based compensation expense	12,792				12,792
Equity Component value of convertible note issuance, net	44,223				44,223
Comprehensive income (loss)	(184,183)					(182,895)	(1,288)
Ending balance (shares) at Jun. 30, 2020		188,461	34,450	231,354
Ending balance at Jun. 30, 2020	$ 1,423,414	$ 62	$ 11	$ 77	$ 1,044,055	$ 450,750	$ (71,541)