Unaudited Consolidated Statements of Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock Class A Common Stock [Member]	Common Stock Class B Convertible Common Stock [Member]	Common Stock Class C Common Stock [Member]	Additional Paid-in-Capital	Retained Earnings	Accumulated Other Comprehensive Income (Loss)
Beginning balance at Dec. 31, 2018	$ 2,016,871	$ 62	$ 11	$ 75	$ 916,628	$ 1,139,082	$ (38,987)
Beginning balance (shares) at Dec. 31, 2018		187,710	34,450	226,422
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of stock options	846				846
Exercise of stock options (shares)		154		178
Shares withheld in consideration of employee tax obligations relative to stock-based compensation arrangements	(3,077)					(3,077)
Shares withheld in consideration of employee tax obligations relative to stock-based compensation arrangements (shares)				(152)
Issuance of common stock, net of forfeitures	1,388			$ 1	1,387
Issuance of common stock, net of forfeitures (shares)		126		2,041
Stock-based compensation expense	12,491				12,491
Comprehensive income (loss)	21,288					22,477	(1,189)
Ending balance at Mar. 31, 2019	2,049,807	$ 62	$ 11	$ 76	931,352	1,158,482	(40,176)
Ending balance (shares) at Mar. 31, 2019		187,980	34,450	228,489
Beginning balance at Dec. 31, 2019	2,150,087	$ 62	$ 11	$ 76	973,717	1,226,986	(50,765)
Beginning balance (shares) at Dec. 31, 2019		188,290	34,450	229,028
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of stock options	484				484
Exercise of stock options (shares)		143		131
Shares withheld in consideration of employee tax obligations relative to stock-based compensation arrangements	(2,853)					(2,853)
Shares withheld in consideration of employee tax obligations relative to stock-based compensation arrangements (shares)		(1)		(176)
Issuance of common stock, net of forfeitures	1,166			$ 1	1,165
Issuance of common stock, net of forfeitures (shares)		19		2,167
Stock-based compensation expense	10,465				10,465
Comprehensive income (loss)	(609,169)					(589,681)	(19,488)
Ending balance at Mar. 31, 2020	$ 1,550,180	$ 62	$ 11	$ 77	$ 985,831	$ 634,452	$ (70,253)
Ending balance (shares) at Mar. 31, 2020		188,451	34,450	231,150