Consolidated Statements of Stockholders' Equity (USD $) In Thousands, unless otherwise specified	Total	Common Stock	Preferred Stock	Paid-In Capital	Other Comprehensive Income (Loss)	Accumulated Deficit
Beginning stockholders' equity at Dec. 31, 2011	$ 222,390	$ 62	$ 1	$ 270,606	$ 4,031	$ (52,310)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Options exercised	260			260
Retirement of shares upon vesting of restricted stock	(1,241)	1		(1,242)
Share-based compensation expense	6,910			6,910
Derivative fair value adjustment, net of tax	(3,510)				(3,510)
Preferred stock dividend	(5,139)					(5,139)
Net income (loss)	(132,079)					(132,079)
Ending stockholders' equity at Dec. 31, 2012	87,591	63	1	276,534	521	(189,528)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Options exercised	731			731
Retirement of shares upon vesting of restricted stock	(1,056)	1		(1,057)
Share-based compensation expense	4,216			4,216
Share-based compensation expense	287			287
Derivative fair value adjustment, net of tax	(1,617)				(1,617)
Preferred stock dividend	(5,139)					(5,139)
Net income (loss)	14,082					14,082
Ending stockholders' equity at Dec. 31, 2013	99,095	64	1	280,711	(1,096)	(180,585)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Options exercised	1,032			1,032
Retirement of shares upon vesting of restricted stock	(1,309)	1		(1,310)
Share-based compensation expense	5,248			5,248
Share-based compensation expense	276			276
Derivative fair value adjustment, net of tax	6,516				6,516
Preferred stock dividend	(5,139)					(5,139)
Net income (loss)	31,190					31,190
Ending stockholders' equity at Dec. 31, 2014	$ 136,909	$ 65	$ 1	$ 285,957	$ 5,420	$ (154,534)