Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock	Preferred Stock	Paid-In Capital	Other Comprehensive Income (Loss)	Accumulated Deficit
Beginning 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
Issuance of shares under employee stock purchase plan	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
Issuance of shares under employee stock purchase plan	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)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Options exercised	61			61
Retirement of shares upon vesting of restricted stock	(451)	1		(452)
Share-based compensation expense	4,617			4,617
Issuance of shares under employee stock purchase plan	199			199
Derivative fair value adjustment, net of tax	(4,473)				(4,473)
Preferred stock dividend	(5,139)					(5,139)
Net income (loss)	(294,790)					(294,790)
Ending stockholders' equity at Dec. 31, 2015	$ (163,067)	$ 66	$ 1	$ 290,382	$ 947	$ (454,463)