Condensed Consolidated Statement of Convertible Preferred Stock and Stockholders' Equity - USD ($) $ in Thousands	Total	Series A convertible preferred stock:	Common stock and additional paid-in-capital:	Common stock and additional paid-in-capital: Cumulative Effect, Period of Adoption, Adjustment	Treasury stock:	Accumulated other comprehensive income (loss):	Accumulated deficit:	Accumulated deficit: Cumulative Effect, Period of Adoption, Adjustment
Beginning balance at Dec. 31, 2020	$ 732,905		$ 3,623,267		$ (80,000)	$ 3,834	$ (2,814,196)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock for equity awards, net of tax withholdings			1,097
Shares withheld for taxes			(8,798)
Accretion of series A convertible preferred stock			(82)
Dividends on series A convertible preferred stock			(4,512)
Stock-based compensation			46,962
Net unrealized loss on investments	(1,795)					(1,795)
Net loss	(50,646)						(50,646)
Ending balance at Mar. 31, 2021	715,131		3,657,934		(80,000)	2,039	(2,864,842)
Beginning balance at Dec. 31, 2020		$ 401,050
Increase (Decrease) in Temporary Equity [Roll Forward]
Series A convertible preferred stock issuance costs		(82)
Accretion of series A convertible preferred stock	82	82
Dividends on series A convertible preferred stock	$ 4,512	4,512
Ending balance at Mar. 31, 2021		405,562
Accounting Standards Update [Extensible Enumeration]	Accounting Standards Update 2020-06 [Member]
Beginning balance at Dec. 31, 2020	$ 732,905		3,623,267		(80,000)	3,834	(2,814,196)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Accretion of series A convertible preferred stock	(100)
Ending balance at Dec. 31, 2021	1,531,240		3,511,467	$ (271,457)	(80,000)	(2,172)	(1,898,055)	$ 202,308
Beginning balance at Dec. 31, 2020		401,050
Ending balance at Dec. 31, 2021	$ 419,404	419,404
Accounting Standards Update [Extensible Enumeration]	Accounting Standards Update 2020-06 [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock for equity awards, net of tax withholdings			1,518
Shares withheld for taxes			(5,834)
Accretion of series A convertible preferred stock	$ 0
Dividends on series A convertible preferred stock			(4,718)
Stock-based compensation			40,088
Net unrealized loss on investments	(11,701)					(11,701)
Net loss	(92,014)						(92,014)
Ending balance at Mar. 31, 2022	1,389,430		$ 3,271,064		$ (80,000)	$ (13,873)	$ (1,787,761)
Increase (Decrease) in Temporary Equity [Roll Forward]
Accretion of series A convertible preferred stock	0
Dividends on series A convertible preferred stock	4,718	4,718
Ending balance at Mar. 31, 2022	$ 424,122	$ 424,122