Unaudited Condensed Consolidated Statements of Changes in Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock [Member]	Additional Paid-In Capital [Member]	Accumulated Deficit [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Treasury Stock, at Cost [Member]
Beginning Balance at Dec. 31, 2017	$ 287,466	$ 926	$ 641,324	$ (194,837)	$ (5,076)	$ (154,871)
Beginning Balance, shares at Dec. 31, 2017		92,637,403
Impact of adoption of ASU 2018-02				1,094	(1,094)
Equity-based compensation	7,545		7,545
Unrealized gain (loss) on derivatives, net of tax	7,491				7,491
Vesting of restricted shares		$ 4	(4)
Vesting of restricted shares, shares		360,092
Shares withheld for tax withholdings	(1,634)	$ (1)	(1,633)
Shares withheld for tax withholdings, shares		(108,432)
Exercise of stock options	7		7
Exercise of stock options, shares		484
Adjustments to previous dividend declarations	47		47
Net income (Loss)	(62,844)			(62,844)
Ending Balance at Mar. 31, 2018	238,078	$ 929	647,286	(256,587)	1,321	(154,871)
Ending Balance, shares at Mar. 31, 2018		92,889,547
Beginning Balance at Dec. 31, 2017	287,466	$ 926	641,324	(194,837)	(5,076)	(154,871)
Beginning Balance, shares at Dec. 31, 2017		92,637,403
Net income (Loss)	55,841
Ending Balance at Sep. 30, 2018	373,336	$ 932	660,231	(137,902)	4,946	(154,871)
Ending Balance, shares at Sep. 30, 2018		93,234,871
Beginning Balance at Mar. 31, 2018	238,078	$ 929	647,286	(256,587)	1,321	(154,871)
Beginning Balance, shares at Mar. 31, 2018		92,889,547
Equity-based compensation	5,892		5,892
Unrealized gain (loss) on derivatives, net of tax	2,476				2,476
Vesting of restricted shares		$ 1	(1)
Vesting of restricted shares, shares		135,114
Shares withheld for tax withholdings	(635)		(635)
Shares withheld for tax withholdings, shares		(28,592)
Exercise of stock options	1,178	$ 1	1,177
Exercise of stock options, shares		64,106
Adjustments to previous dividend declarations	(5)		(5)
Net income (Loss)	22,697			22,697
Ending Balance at Jun. 30, 2018	269,681	$ 931	653,714	(233,890)	3,797	(154,871)
Ending Balance, shares at Jun. 30, 2018		93,060,175
Equity-based compensation	5,183		5,183
Unrealized gain (loss) on derivatives, net of tax	1,149				1,149
Vesting of restricted shares		$ 1	(1)
Vesting of restricted shares, shares		86,922
Shares withheld for tax withholdings	(673)	$ (1)	(672)
Shares withheld for tax withholdings, shares		(23,758)
Exercise of stock options	2,006	$ 1	2,005
Exercise of stock options, shares		111,532
Adjustments to previous dividend declarations	2		2
Net income (Loss)	95,988			95,988
Ending Balance at Sep. 30, 2018	373,336	$ 932	660,231	(137,902)	4,946	(154,871)
Ending Balance, shares at Sep. 30, 2018		93,234,871
Beginning Balance at Dec. 31, 2018	$ 265,194	$ 934	663,834	(148,955)	2,284	(252,903)
Beginning Balance, shares at Dec. 31, 2018	93,400,929	93,400,929
Equity-based compensation	$ 3,198		3,198
Unrealized gain (loss) on derivatives, net of tax	(2,064)				(2,064)
Vesting of restricted shares		$ 4	(4)
Vesting of restricted shares, shares		440,646
Shares withheld for tax withholdings	(3,606)	$ (1)	(3,605)
Shares withheld for tax withholdings, shares		(132,886)
Exercise of stock options	715		715
Exercise of stock options, shares		39,928
Adjustments to previous dividend declarations	3		3
Net income (Loss)	(37,020)			(37,020)
Ending Balance at Mar. 31, 2019	226,420	$ 937	664,141	(185,975)	220	(252,903)
Ending Balance, shares at Mar. 31, 2019		93,748,617
Beginning Balance at Dec. 31, 2018	$ 265,194	$ 934	663,834	(148,955)	2,284	(252,903)
Beginning Balance, shares at Dec. 31, 2018	93,400,929	93,400,929
Exercise of stock options, shares	198,437
Net income (Loss)	$ 113,659
Ending Balance at Sep. 30, 2019	$ 231,703	$ 940	671,234	(35,296)	(2,272)	(402,903)
Ending Balance, shares at Sep. 30, 2019	94,012,743	94,012,743
Beginning Balance at Mar. 31, 2019	$ 226,420	$ 937	664,141	(185,975)	220	(252,903)
Beginning Balance, shares at Mar. 31, 2019		93,748,617
Equity-based compensation	4,084		4,084
Unrealized gain (loss) on derivatives, net of tax	(2,866)				(2,866)
Vesting of restricted shares		$ 1	(1)
Vesting of restricted shares, shares		57,642
Shares withheld for tax withholdings	(362)		(362)
Shares withheld for tax withholdings, shares		(12,536)
Exercise of stock options	1,620	$ 1	1,619
Exercise of stock options, shares		91,248
Adjustments to previous dividend declarations	1		1
Repurchase of treasury shares	(150,000)					(150,000)
Net income (Loss)	52,651			52,651
Ending Balance at Jun. 30, 2019	131,548	$ 939	669,482	(133,324)	(2,646)	(402,903)
Ending Balance, shares at Jun. 30, 2019		93,884,971
Equity-based compensation	1,162		1,162
Unrealized gain (loss) on derivatives, net of tax	374				374
Vesting of restricted shares		$ 1	(1)
Vesting of restricted shares, shares		83,697
Shares withheld for tax withholdings	(653)	$ (1)	(652)
Shares withheld for tax withholdings, shares		(23,186)
Exercise of stock options	1,243	$ 1	1,242
Exercise of stock options, shares		67,261
Adjustments to previous dividend declarations	1		1
Net income (Loss)	98,028			98,028
Ending Balance at Sep. 30, 2019	$ 231,703	$ 940	$ 671,234	$ (35,296)	$ (2,272)	$ (402,903)
Ending Balance, shares at Sep. 30, 2019	94,012,743	94,012,743