Consolidated Statements of Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands	Total	Regular Dividend	Common Stock	Additional Paid-in Capital	(Accumulated Deficit) Retained Earnings	(Accumulated Deficit) Retained Earnings Regular Dividend
BALANCE (in shares) at Dec. 31, 2014			116,764
BALANCE at Dec. 31, 2014	$ 1,481,500		$ 1,168	$ 1,748,303	$ (267,971)
Net income	57,277				57,277
Retirement of common stock (in shares)			(230)
Retirement of common stock	(9,261)		$ (2)	(9,259)
Dividend on common stock		$ (63,621)				$ (63,621)
Restricted stock compensation, net of forfeitures (in shares)			(3)
Restricted stock compensation, net of forfeitures	3,426			3,392	34
Income tax benefit of equity compensation	379			379
Stock option compensation expense, net of forfeitures	372			372
Restricted stock grants (in shares)			293
Restricted stock grants	3		$ 3
Stock options exercised (in shares)			176
Stock options exercised	3,541		$ 1	3,540
BALANCE (in shares) at Mar. 31, 2015			117,000
BALANCE at Mar. 31, 2015	1,473,616		$ 1,170	1,746,727	(274,281)
BALANCE (in shares) at Dec. 31, 2015			117,232
BALANCE at Dec. 31, 2015	1,462,748		$ 1,172	1,762,394	(300,818)
Net income	46,307				46,307
Retirement of common stock (in shares)			(120)
Retirement of common stock	(3,528)		$ (1)	(3,527)
Dividend on common stock		$ (63,950)				$ (63,950)
Restricted stock compensation, net of forfeitures (in shares)			(1)
Restricted stock compensation, net of forfeitures	3,693			3,636	57
Income tax benefit of equity compensation	16			16
Stock option compensation expense, net of forfeitures	88			88
Restricted stock grants (in shares)			307
Restricted stock grants	3		$ 3
Stock options exercised (in shares)			59
Stock options exercised	1,079		$ 1	1,078
BALANCE (in shares) at Mar. 31, 2016			117,477
BALANCE at Mar. 31, 2016	$ 1,446,456		$ 1,175	$ 1,763,685	$ (318,404)