Consolidated Statements of Changes in Equity (USD $) In Thousands	Total	Series A Preferred Stock [Member]	Series C Preferred Stock [Member]	Preferred Stock [Member] Series A Preferred Stock [Member]	Preferred Stock [Member] Series C Preferred Stock [Member]	Common Stock [Member]	Additional Paid-In Capital [Member]	Additional Paid-In Capital [Member] Series A Preferred Stock [Member]	Additional Paid-In Capital [Member] Series C Preferred Stock [Member]	Treasury Stock [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Accumulated Deficit [Member]
Balance at Dec. 31, 2012	$ 3,569,431			$ 957,327		$ 113,182	$ 2,868,965			$ (114,176)	$ 4,101	$ (259,968)
Net income	75,109											75,109
Other comprehensive income (loss), net of income taxes	(37,161)										(37,161)
Cash dividends declared on Common Stock - $0.14 per share	(16,981)											(16,981)
Cash dividends paid on Preferred Stock		(24,197)						(24,197)
Accretion of discount on Series A Preferred Stock				5,398				(5,398)
Settlement of prepaid common stock purchase contracts						17,550	(17,550)
Restricted share unit activity	(1,481)					146	(1,490)					(137)
Stock options exercised	134					9	125
Share-based compensation expense	3,350						3,350
Balance at Jun. 30, 2013	3,568,204			962,725		130,887	2,823,805			(114,176)	(33,060)	(201,977)
Balance at Dec. 31, 2013	2,948,985				125,862	139,721	2,976,348			(114,176)	(41,258)	(137,512)
Net income	95,289											95,289
Other comprehensive income (loss), net of income taxes	27,542										27,542
Cash dividends declared on Common Stock - $0.14 per share	(19,460)											(19,460)
Cash dividends paid on Preferred Stock			(5,119)						(5,119)
Issuance of stock, net of issuance costs			118		118
Restricted share unit activity	(468)					39	(507)
Stock options exercised	1,304					75	1,229
Share-based compensation tax benefit	162						162
Share-based compensation expense	4,698						4,698
Balance at Jun. 30, 2014	$ 3,053,051				$ 125,980	$ 139,835	$ 2,976,811			$ (114,176)	$ (13,716)	$ (61,683)