CONSOLIDATED STATEMENT OF CHANGES IN STOCKHOLDERS' EQUITY (USD $) In Thousands	Total	Common Stock	Treasury Stock	Additional Paid-In Capital	Retained Earnings	Accumulated Other Comprehensive Income (Loss)
Beginning Balance at Dec. 31, 2009	$ 325,659	$ 475	$ (860)	$ 1,324,410	$ (982,986)	$ (15,380)
Net income	96,429				96,429
Adjustment for fair value accounting of derivatives, net of tax	1,176					1,176
Exercise of stock options and vesting of restricted stock	(1,367)	3		(1,370)
Amortization of stock compensation expense expense	8,462			8,462
Net tax benefit from stock option exercises and restricted stock vesting	(2)			(2)
Ending Balance at Dec. 31, 2010	430,357	478	(860)	1,331,500	(886,557)	(14,204)
Net income	194,332				194,332
Adjustment for fair value accounting of derivatives, net of tax	36,072					36,072
Exercise of stock options and vesting of restricted stock	(2,581)	3		(2,584)
Amortization of stock compensation expense expense	8,914			8,914
Net tax benefit from stock option exercises and restricted stock vesting	735			735
Ending Balance at Dec. 31, 2011	667,829	481	(860)	1,338,565	(692,225)	21,868
Net income	149,426				149,426
Adjustment for fair value accounting of derivatives, net of tax	6,965					6,965
Exercise of stock options and vesting of restricted stock	(3,773)	3		(3,776)
Amortization of stock compensation expense expense	12,792			12,792
Net tax benefit from stock option exercises and restricted stock vesting	814			814
Convertible notes offering	38,080			38,080
Ending Balance at Dec. 31, 2012	$ 872,133	$ 484	$ (860)	$ 1,386,475	$ (542,799)	$ 28,833