STOCKHOLDERS' EQUITY (Details 3) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended			6 Months Ended
	Jun. 30, 2012		Jun. 30, 2011	Jun. 30, 2012		Jun. 30, 2011	Dec. 31, 2011
STOCKHOLDERS' EQUITY
Common stock, shares outstanding	142,645,812			142,645,812			149,327,907
Earnings per share calculations
Net income	$ 70,557		$ 60,525	$ 138,640		$ 116,596
Less: Preferred stock dividends	(1,714)		(1,714)	(3,428)		(3,429)
Less: Earnings allocated to participating securities	(859)			(1,718)
Net income after adjustments for dividends on preferred stock (declared in the period) and/or cumulative preferred stock (accumulated for the period) and participating securities.	67,984	[1]	58,811	133,494	[1]	113,167
Effect of dilutive securities
Restricted stock awards	7		35	15		41
Convertible preferred stock	1,714		1,714	3,428		3,429
Diluted EPS - income available to common stockholders	$ 69,705	[1]	$ 60,560	$ 136,937	[1]	$ 116,637
Number of Shares
Weighted average shares outstanding	142,107,000	[1]	147,011,000	143,727,000	[1]	146,937,000
Effect of dilutive securities on weighted average shares outstanding
Stock options (in shares)	36,000		73,000	41,000		96,000
Restricted stock awards (in shares)	72,000		692,000	75,000		685,000
Convertible preferred stock (in shares)	5,571,000		5,571,000	5,571,000		5,571,000
Stock warrants (in shares)						60,000
Total weighted average diluted shares outstanding	147,786,000	[1]	153,347,000	149,414,000	[1]	153,349,000
Per Share Amounts
Basic EPS (in dollars per share)	$ 0.48	[1]	$ 0.40	$ 0.93	[1]	$ 0.77
Diluted EPS - Income available to common stockholders (in dollars per share)	$ 0.47	[1]	$ 0.39	$ 0.92	[1]	$ 0.76

[1] On April 1, 2012, the Company revised its calculation of earnings per share to account for participating securities under the two-class method. This revision to the earnings per share calculation does not have an impact to previous periods as the amounts are immaterial.