Unaudited Condensed Consolidated Statement of Changes in Stockholders' Equity - 6 months ended Jun. 30, 2018 - 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, 2017	$ 287,466	$ 926	$ 641,324	$ (194,837)	$ (5,076)	$ (154,871)
Beginning Balance, shares at Dec. 31, 2017	92,637,403	92,637,403
Impact of adoption of ASU 2018-02				1,094	(1,094)
Equity-based compensation	$ 13,437		13,437
Unrealized gain on derivatives, net of tax	9,967				9,967
Vesting of restricted shares		$ 5	(5)
Vesting of restricted shares, shares		495,206
Shares withheld for tax withholdings	(2,269)	$ (1)	(2,268)
Shares withheld for tax withholdings, shares		(137,024)
Exercise of stock options	$ 1,185	$ 1	1,184
Exercise of stock options, shares	64,590	64,590
Adjustments to previous dividend declarations	$ 42		42
Net loss	(40,147)			(40,147)
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	93,060,175