CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Common Stock	Common stock held in treasury	Additional Paid-in Capital	Retained (deficit)/earnings	Accumulated other comprehensive loss
Beginning balance at Dec. 31, 2018	$ 4,059,431	$ 2,495	$ (391)	$ 5,628,447	$ (1,570,462)	$ (658)
Beginning balance Shares at Dec. 31, 2018		249,520,000
Issuance of common stock	342	$ 19		323
Issuance of common stock, shares		1,919,000
Issuance of common stock upon vesting of PSUs				5	(5)
Stock-based compensation expense	31,120			31,120
Cash dividends paid ($0.08 per share)	(20,070)				(20,070)
Treasury stock issuance			63	(63)
Treasury stock repurchased	(6,908)		(6,908)
Other comprehensive income (loss)	(130)					(130)
Net loss	(1,716,297)				(1,716,297)
Ending balance at Dec. 31, 2019	2,347,488	$ 2,514	(7,236)	5,659,832	(3,306,834)	(788)
Ending balance Shares at Dec. 31, 2019		251,439,000
Issuance of common stock	(893)	$ 49		(942)
Issuance of common stock, shares		4,896,000
Issuance of common stock upon vesting of PSUs				74	(74)
Issuance of common stock upon vesting of PSUs, shares		19,000
Stock-based compensation expense	25,400			25,400
Treasury stock issuance			96	(96)
Treasury stock repurchased	(22,992)		(22,992)
Other comprehensive income (loss)	309					309
Net loss	(711,777)				(711,777)
Ending balance at Dec. 31, 2020	$ 1,637,535	$ 2,563	(30,132)	5,684,268	(4,018,685)	(479)
Ending balance Shares at Dec. 31, 2020	256,353,887	256,354
Issuance of common stock	$ 7,033	$ 35		6,998
Issuance of common stock, shares		3,429,000
Issuance of common stock upon vesting of PSUs				148	(148)
Issuance of common stock upon vesting of PSUs, shares		13,000
Stock-based compensation expense	28,988			28,988
Treasury stock issuance			125	(125)
Other comprehensive income (loss)	329					329
Net loss	411,778				411,778
Ending balance at Dec. 31, 2021	$ 2,085,663	$ 2,598	$ (30,007)	$ 5,720,277	$ (3,607,055)	$ (150)
Ending balance Shares at Dec. 31, 2021	259,795,554	259,796