CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY (USD $) In Thousands, unless otherwise specified	Total	Additional Paid In Capital Preferred Stock	Common Stock	Additional Paid In Capital Common Stock	Retained Earnings	Treasury Stock	Accumulated Other Comprehensive (Loss) Income, Net of Tax
BALANCE at Dec. 31, 2011	$ 2,311,743	$ 83,027	$ 157	$ 1,443,883	$ 934,617	$ (116,001)	$ (33,940)
Increase (Decrease) in Stockholders' Equity
Net income	209,750				209,750
Other comprehensive income (loss)	32,423						32,423
Stock compensation costs	11,567			11,567
Tax benefit from stock compensation plans, net	461			461
Issuance of 285,921 and 299,964 shares of common stock pursuant to various stock compensation plans and agreements for the period ended September 30, 2013 and 2012, respectively	3,136			3,136
Issuance of 19,998 and 26,151 shares pursuant to Director retainer fee for the period ended September 30, 2013 and 2012, respectively	570			570
Cancellation of 58,929 and 154,508 shares of common stock due to forfeitures of issued restricted stock for the period ended September 30, 2013 and 2012, respectively				2,653		(2,653)
368,932 and 130,577 shares of restricted stock surrendered due to employee tax liability for the period ended September 30, 2013 and 2012, respectively	(2,867)					(2,867)
Preferred stock dividends	(5,142)				(5,142)
Common stock dividends	(43,482)				(43,482)
Purchase of 8,026,807 and 9,068,105 shares of treasury stock pursuant to the Stock Repurchase Program for the period ended September 30, 2013 and 2012, respectively	(199,950)					(199,950)
BALANCE at Sep. 30, 2012	2,318,209	83,027	157	1,462,270	1,095,743	(321,471)	(1,517)
BALANCE at Dec. 31, 2012	2,382,122	83,027	157	1,464,739	1,151,828	(322,298)	4,669
Increase (Decrease) in Stockholders' Equity
Net income	219,263				219,263
Other comprehensive income (loss)	(29,847)						(29,847)
Stock compensation costs	9,263			9,263
Tax benefit from stock compensation plans, net	3,301			3,301
Issuance of 285,921 and 299,964 shares of common stock pursuant to various stock compensation plans and agreements for the period ended September 30, 2013 and 2012, respectively	2,112			2,112
Issuance of 19,998 and 26,151 shares pursuant to Director retainer fee for the period ended September 30, 2013 and 2012, respectively	630			630
Cancellation of 58,929 and 154,508 shares of common stock due to forfeitures of issued restricted stock for the period ended September 30, 2013 and 2012, respectively				1,039		(1,039)
368,932 and 130,577 shares of restricted stock surrendered due to employee tax liability for the period ended September 30, 2013 and 2012, respectively	(9,049)					(9,049)
Preferred stock dividends	(3,428)				(3,428)
Common stock dividends	(62,499)				(62,499)
Conversion of 85,710 shares of Series A preferred stock into 5,594,080 shares of common stock		(83,027)	6	83,021
Purchase of 8,026,807 and 9,068,105 shares of treasury stock pursuant to the Stock Repurchase Program for the period ended September 30, 2013 and 2012, respectively	(199,992)					(199,992)
BALANCE at Sep. 30, 2013	$ 2,311,876		$ 163	$ 1,564,105	$ 1,305,164	$ (532,378)	$ (25,178)