Unaudited Condensed Consolidated Statements of Changes in Stockholders' Equity (Deficit) - USD ($) $ in Thousands	Total	Common Stock [Member]	Additional Paid-In Capital [Member]	Accumulated Deficit [Member]	Accumulated Other Comprehensive (Loss) Income [Member]	Treasury Stock, at Cost [Member]
Beginning Balance at Dec. 31, 2019	$ 210,892	$ 940	$ 673,893	$ (59,479)	$ (1,559)	$ (402,903)
Beginning Balance, shares at Dec. 31, 2019		94,044,203
Equity-based compensation	(3,601)		(3,601)
Unrealized gain on derivatives, net of tax	704				704
Vesting of restricted shares		$ 4	(4)
Vesting of restricted shares, shares		410,807
Shares withheld for tax withholdings	(3,160)	$ (1)	(3,159)
Shares withheld for tax withholdings, shares		(121,089)
Exercise of stock options	203		203
Exercise of stock options, shares		11,096
Adjustments to previous dividend declarations	1		1
Repurchase of treasury shares	(12,406)					(12,406)
Net income (Loss)	(56,519)			(56,519)
Ending Balance at Mar. 31, 2020	136,114	$ 943	667,333	(115,998)	(855)	(415,309)
Ending Balance, shares at Mar. 31, 2020		94,345,017
Beginning Balance at Dec. 31, 2019	210,892	$ 940	673,893	(59,479)	(1,559)	(402,903)
Beginning Balance, shares at Dec. 31, 2019		94,044,203
Unrealized gain on derivatives, net of tax	1,559
Net income (Loss)	(266,785)
Ending Balance at Sep. 30, 2020	(66,521)	$ 944	674,108	(326,264)		(415,309)
Ending Balance, shares at Sep. 30, 2020		94,433,197
Beginning Balance at Mar. 31, 2020	136,114	$ 943	667,333	(115,998)	(855)	(415,309)
Beginning Balance, shares at Mar. 31, 2020		94,345,017
Equity-based compensation	3,320		3,320
Unrealized gain on derivatives, net of tax	855				$ 855
Vesting of restricted shares		$ 1	(1)
Vesting of restricted shares, shares		71,530
Shares withheld for tax withholdings	(154)		(154)
Shares withheld for tax withholdings, shares		(8,987)
Exercise of stock options	15		15
Exercise of stock options, shares		818
Net income (Loss)	(131,029)			(131,029)
Ending Balance at Jun. 30, 2020	9,121	$ 944	670,513	(247,027)		(415,309)
Ending Balance, shares at Jun. 30, 2020		94,408,378
Equity-based compensation	3,484		3,484
Vesting of restricted shares, shares		18,818
Shares withheld for tax withholdings	(36)		(36)
Shares withheld for tax withholdings, shares		(1,999)
Exercise of stock options	147		147
Exercise of stock options, shares		8,000
Net income (Loss)	(79,237)			(79,237)
Ending Balance at Sep. 30, 2020	(66,521)	$ 944	674,108	(326,264)		(415,309)
Ending Balance, shares at Sep. 30, 2020		94,433,197
Beginning Balance at Dec. 31, 2020	$ (105,803)	$ 946	680,360	(371,800)		(415,309)
Beginning Balance, shares at Dec. 31, 2020	94,652,248	94,652,248
Equity-based compensation	$ 4,473		4,473
Vesting of restricted shares		$ 1	(1)
Vesting of restricted shares, shares		130,834
Shares withheld for tax withholdings	(1,971)		(1,971)
Shares withheld for tax withholdings, shares		(41,271)
Exercise of stock options	2,393	$ 1	2,392
Exercise of stock options, shares		116,634
Net income (Loss)	(44,884)			(44,884)
Ending Balance at Mar. 31, 2021	(145,792)	$ 948	685,253	(416,684)		(415,309)
Ending Balance, shares at Mar. 31, 2021		94,858,445
Beginning Balance at Dec. 31, 2020	$ (105,803)	$ 946	680,360	(371,800)		(415,309)
Beginning Balance, shares at Dec. 31, 2020	94,652,248	94,652,248
Net income (Loss)	$ 184,975
Ending Balance at Sep. 30, 2021	$ 11,477	$ 954	695,374	(186,825)		(498,026)
Ending Balance, shares at Sep. 30, 2021	95,419,927	95,419,927
Beginning Balance at Mar. 31, 2021	$ (145,792)	$ 948	685,253	(416,684)		(415,309)
Beginning Balance, shares at Mar. 31, 2021		94,858,445
Equity-based compensation	5,634		5,634
Vesting of restricted shares		$ 7	(7)
Vesting of restricted shares, shares		653,146
Shares withheld for tax withholdings	(10,557)	$ (3)	(10,554)
Shares withheld for tax withholdings, shares		(213,601)
Exercise of stock options	1,639	$ 1	1,638
Exercise of stock options, shares		82,491
Net income (Loss)	127,762			127,762
Ending Balance at Jun. 30, 2021	(21,314)	$ 953	681,964	(288,922)		(415,309)
Ending Balance, shares at Jun. 30, 2021		95,380,481
Equity-based compensation	13,049		13,049
Vesting of restricted shares, shares		14,945
Shares withheld for tax withholdings	(171)		(171)
Shares withheld for tax withholdings, shares		(3,427)
Exercise of stock options	533	$ 1	532
Exercise of stock options, shares		27,928
Repurchase of treasury shares	(82,717)					(82,717)
Net income (Loss)	102,097			102,097
Ending Balance at Sep. 30, 2021	$ 11,477	$ 954	$ 695,374	$ (186,825)		$ (498,026)
Ending Balance, shares at Sep. 30, 2021	95,419,927	95,419,927