Consolidated Statements of Common Stockholders' Equity (USD $) In Thousands, except Share data	Total	Common Stock	Other Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Loss	Treasury Stock
Balance at Dec. 31, 2009	$ 2,556,647	$ 188,389	$ 1,015,678	$ 1,377,039	$ (20,833)	$ (3,626)
Treasury stock (in shares) at Dec. 31, 2009						(538,921)
Balance (in shares) at Dec. 31, 2009		188,389,265
Net income (loss)	240,659		0	240,659	0
Other comprehensive loss	(10,428)		0	0	(10,428)
Dividends declared on preferred stocks	(685)		0	(685)	0
Dividends declared on common stock	(119,574)		0	(119,574)	0
Stock-based compensation		426,610
Stock-based compensation	8,694	427	8,267	0	0
Tax benefit (deficit) on stock-based compensation	924		924	0	0
Issuance of common stock		85,504
Issuance of common stock	1,565	85	1,480	0	0
Balance at Dec. 31, 2010	2,677,802	188,901	1,026,349	1,497,439	(31,261)	(3,626)
Treasury stock (in shares) at Dec. 31, 2010						(538,921)
Balance (in shares) at Dec. 31, 2010		188,901,379
Net income (loss)	213,026		0	213,026	0
Other comprehensive loss	(15,740)		0	0	(15,740)
Dividends declared on preferred stocks	(685)		0	(685)	0
Dividends declared on common stock	(123,657)		0	(123,657)	0
Stock-based compensation		423,591
Stock-based compensation	10,588	424	10,164	0	0
Tax benefit (deficit) on stock-based compensation	(909)		(909)	0	0
Issuance of common stock		7,515
Issuance of common stock	142	7	135	0	0
Balance at Dec. 31, 2011	2,760,567	189,332	1,035,739	1,586,123	(47,001)	(3,626)
Treasury stock (in shares) at Dec. 31, 2011	(538,921)					(538,921)
Balance (in shares) at Dec. 31, 2011	189,332,485	189,332,485
Net income (loss)	(754)		0	(754)	0
Other comprehensive loss	(1,720)		0	0	(1,720)
Dividends declared on preferred stocks	(685)		0	(685)	0
Dividends declared on common stock	(127,538)		0	(127,538)	0
Stock-based compensation		25,743
Stock-based compensation	5,120	26	5,094	0	0
Tax benefit (deficit) on stock-based compensation	(1,958)		(1,958)	0	0
Issuance of common stock		11,222
Issuance of common stock	216	11	205	0	0
Balance at Dec. 31, 2012	$ 2,633,248	$ 189,369	$ 1,039,080	$ 1,457,146	$ (48,721)	$ (3,626)
Treasury stock (in shares) at Dec. 31, 2012	(538,921)					(538,921)
Balance (in shares) at Dec. 31, 2012	189,369,450	189,369,450