STOCKHOLDERS' EQUITY (Details 2) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2013		Mar. 31, 2012	Dec. 31, 2012
STOCKHOLDERS' EQUITY
Common stock, shares outstanding	136,578,350			140,294,092
Earnings per share calculations
Net income	$ 72,091		$ 68,083
Less: Preferred stock dividends	(1,714)		(1,714)
Less: Earnings allocated to participating securities	(584)
Basic EPS - income allocated to common stockholders	69,793	[1]	66,369
Effect of dilutive securities
Restricted stock awards	36		103
Convertible preferred stock	1,714		1,714
Diluted EPS - income allocated to common stockholders	$ 71,543	[1]	$ 68,186
Number of Shares
Weighted average shares outstanding	137,648,000		145,347,000
Effect of dilutive securities on weighted average shares outstanding
Stock options (in shares)	51,000		48,000
Restricted stock awards (in shares)	242,000		1,030,000
Convertible preferred stock (in shares)	5,578,000		5,571,000
Total weighted average diluted shares outstanding	143,519,000		151,996,000
Per Share Amounts
Basic EPS (in dollars per share)	$ 0.51		$ 0.46
Diluted EPS - Income available to common stockholders (in dollars per share)	$ 0.50		$ 0.45

[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.