CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS’ EQUITY (UNAUDITED) (in thousands, except share data and dividends per share) - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Retained Earnings (Deficit)	Accumulated Other Comprehensive Loss
Cash dividends declared per share	$ 0.01
Balances, Common Stock, Shares, Outstanding, Beginning at Dec. 31, 2019		112,987,952
Balances, Total Stockholders' Equity, Beginning at Dec. 31, 2019	$ 2,748,994	$ 1,130	$ 1,791,596	$ 967,587	$ (11,319)
Increase (Decrease) in Stockholders' Equity
Net loss	(411,895)			(411,895)
Other comprehensive income	190				190
Cash dividends	(1,130)			(1,130)
Issuance of common stock upon vesting of RSUs, net of shares used for tax withholdings (Shares)		730
Issuance of common stock upon vesting of RSUs, net of shares used for tax withholdings (Amount)	(3)	$ 0	(3)
Stock-based compensation expense	5,561		5,561
Balances, Common Stock, Shares, Outstanding, Ending at Mar. 31, 2020		112,988,682
Balances, Total Stockholders' Equity, Ending at Mar. 31, 2020	$ 2,341,717	$ 1,130	1,797,154	554,562	(11,129)
Cash dividends declared per share	$ 0.01
Balances, Common Stock, Shares, Outstanding, Beginning at Dec. 31, 2019		112,987,952
Balances, Total Stockholders' Equity, Beginning at Dec. 31, 2019	$ 2,748,994	$ 1,130	1,791,596	967,587	(11,319)
Increase (Decrease) in Stockholders' Equity
Net loss	(501,147)
Other comprehensive income	378
Balances, Common Stock, Shares, Outstanding, Ending at Jun. 30, 2020		113,553,271
Balances, Total Stockholders' Equity, Ending at Jun. 30, 2020	$ 2,280,832	$ 1,136	1,825,327	465,310	(10,941)
Cash dividends declared per share	$ 0
Balances, Common Stock, Shares, Outstanding, Beginning at Mar. 31, 2020		112,988,682
Balances, Total Stockholders' Equity, Beginning at Mar. 31, 2020	$ 2,341,717	$ 1,130	1,797,154	554,562	(11,129)
Increase (Decrease) in Stockholders' Equity
Net loss	(89,252)			(89,252)
Other comprehensive income	188				188
Issuance of common stock under Employee Stock Purchase Plan (Shares)		297,013
Issuance of common stock under Employee Stock Purchase Plan (Amount)	947	$ 3	944
Stock-based compensation expense (shares)		267,576
Stock-based compensation expense	5,712	$ 3	5,709
Issuance of Warrants	21,520		21,520
Balances, Common Stock, Shares, Outstanding, Ending at Jun. 30, 2020		113,553,271
Balances, Total Stockholders' Equity, Ending at Jun. 30, 2020	$ 2,280,832	$ 1,136	1,825,327	465,310	(10,941)
Cash dividends declared per share	$ 0.01
Balances, Common Stock, Shares, Outstanding, Beginning at Dec. 31, 2020	114,742,304	114,742,304
Balances, Total Stockholders' Equity, Beginning at Dec. 31, 2020	$ 2,016,160	$ 1,147	1,827,914	200,697	(13,598)
Increase (Decrease) in Stockholders' Equity
Net loss	(251,269)			(251,269)
Other comprehensive income	191				191
Cash dividends	(1,147)			(1,147)
Stock-based compensation expense	5,737		5,737
Balances, Common Stock, Shares, Outstanding, Ending at Mar. 31, 2021		114,742,304
Balances, Total Stockholders' Equity, Ending at Mar. 31, 2021	$ 1,769,672	$ 1,147	1,833,651	(51,719)	(13,407)
Cash dividends declared per share	$ 0.01
Balances, Common Stock, Shares, Outstanding, Beginning at Dec. 31, 2020	114,742,304	114,742,304
Balances, Total Stockholders' Equity, Beginning at Dec. 31, 2020	$ 2,016,160	$ 1,147	1,827,914	200,697	(13,598)
Increase (Decrease) in Stockholders' Equity
Net loss	(474,264)
Other comprehensive income	$ 783
Balances, Common Stock, Shares, Outstanding, Ending at Jun. 30, 2021	120,970,853	120,970,853
Balances, Total Stockholders' Equity, Ending at Jun. 30, 2021	$ 1,552,509	$ 1,210	1,838,859	(274,745)	(12,815)
Cash dividends declared per share	$ 0
Cash dividends paid per share	$ 0.01
Balances, Common Stock, Shares, Outstanding, Beginning at Mar. 31, 2021		114,742,304
Balances, Total Stockholders' Equity, Beginning at Mar. 31, 2021	$ 1,769,672	$ 1,147	1,833,651	(51,719)	(13,407)
Increase (Decrease) in Stockholders' Equity
Net loss	(222,995)			(222,995)
Other comprehensive income	592				592
Cash dividends	(31)			(31)
Issuance of common stock under Employee Stock Purchase Plan (Shares)		252,665
Issuance of common stock under Employee Stock Purchase Plan (Amount)	1,315	$ 3	1,312
Stock-based compensation expense (shares)		57,795
Stock-based compensation expense	3,956	$ 1	3,955
Issuance of common stock through cashless exercise of warrants (Shares)		5,918,089
Issuance of common stock through cashless exercise of warrants (Amount)	$ 0	$ 59	(59)
Balances, Common Stock, Shares, Outstanding, Ending at Jun. 30, 2021	120,970,853	120,970,853
Balances, Total Stockholders' Equity, Ending at Jun. 30, 2021	$ 1,552,509	$ 1,210	$ 1,838,859	$ (274,745)	$ (12,815)