STOCKHOLDERS' EQUITY AND EARNINGS PER SHARE (Details 3) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2010	Sep. 30, 2010	Jun. 30, 2010	Mar. 31, 2010	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Earnings per share calculations
Net income									$ 245,234	$ 164,564	$ 82,008
Less: Preferred stock dividends and amortization of preferred stock discount	(1,714)	(1,714)	(1,714)	(1,715)	(24,109)	(6,732)	(6,147)	(6,138)	(6,857)	(43,126)	(49,115)
Income available to common stockholders before extraordinary item											32,893
Extraordinary item - impact of desecuritization											(5,366)
Basic EPS - income available to common stockholders	64,492	60,718	58,811	54,356	32,240	40,219	30,201	18,778	238,377	121,438	27,527
Effect of dilutive securities
Restricted stock									115	15
Convertible preferred stock									6,857
Income available to common stockholders before extraordinary item											32,893
Income impact of assumed conversions											2
Extraordinary item - impact of desecuritization											(5,366)
Diluted EPS - income available to common stockholders									$ 245,349	$ 121,453	$ 27,529
Number of Shares
Weighted average shares outstanding (in shares)									147,093	137,478	78,770
Effect of dilutive securities on weighted average shares outstanding
Stock options (in shares)									62	142	15
Restricted stock (in shares)									718	370	51
Convertible preferred stock (in shares)									5,571	8,936	5,687
Stock warrants (in shares)									23	176
Total weighted average diluted shares outstanding (in shares)									153,467	147,102	84,523
Per Share Amounts
Basic EPS - Income available to common stockholders before extraordinary item (per share)											$ 0.42
Extraordinary item - impact of desecuritization, Basic (in dollars per share)											$ (0.07)
Basic EPS (in dollars per share)	$ 0.44	$ 0.41	$ 0.40	$ 0.37	$ 0.22	$ 0.27	$ 0.21	$ 0.17	$ 1.62	$ 0.88	$ 0.35
Diluted EPS - Income available to common stockholders before extraordinary item (per share)											$ 0.39
Extraordinary item - impact of desecuritization, Diluted (in dollars per share)											$ (0.06)
Diluted EPS (in dollars per share)	$ 0.43	$ 0.41	$ 0.39	$ 0.37	$ 0.22	$ 0.27	$ 0.21	$ 0.13	$ 1.60	$ 0.83	$ 0.33