Unaudited Condensed Consolidated Statement of Changes in Stockholders' Equity - 9 months ended Sep. 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	$ 18,620		18,620
Unrealized gain on derivatives, net of tax	11,116				11,116
Vesting of restricted shares		$ 6	(6)
Vesting of restricted shares, shares		582,128
Shares withheld for tax withholdings	(2,942)	$ (2)	(2,940)
Shares withheld for tax withholdings, shares		(160,782)
Exercise of stock options	$ 3,191	$ 2	3,189
Exercise of stock options, shares	176,122	176,122
Adjustments to previous dividend declarations	$ 44		44
Net income	55,841			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	93,234,871