Consolidated Statements Of Changes In Shareholders' Equity (USD $) In Thousands, except Share data, unless otherwise specified	Total	Preferred Stock [Member]	Common Stock [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Noncontrolling Interests [Member]
Balance at Dec. 31, 2010	$ 6,647,214	$ 2,056,672	$ 4,163,619	$ 889,284	$ (461,296)	$ (1,065)
Balance (in shares) at Dec. 31, 2010			182,784,086
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss) for the period	125,201			125,692		(491)
Other comprehensive income (loss)	(43,195)				(43,195)
Issuance of stock	25,048		25,048
Subordinated debt converted to preferred stock	224,318	262,062	(37,744)
Issuance of common stock (in shares)			1,067,540
Net activity under employee plans and related tax benefits	7,446		7,446
Net activity under employee plans and related tax benefits (in shares)			(459,664)
Dividends on preferred stock	(71,251)	10,636		(81,887)
Dividends on common stock, $0.02 per share	(3,653)			(3,653)
Change in deferred compensation	1,909			1,909
Other changes in noncontrolling interests	54					54
Balance at Jun. 30, 2011	6,913,091	2,329,370	4,158,369	931,345	(504,491)	(1,502)
Balance (in shares) at Jun. 30, 2011			184,311,290
Balance at Dec. 31, 2011	6,983,228	2,377,560	4,163,242	1,036,590	(592,084)	(2,080)
Balance (in shares) at Dec. 31, 2011	184,135,388		184,135,388
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss) for the period	180,867			181,413		(546)
Other comprehensive income (loss)	15,937				15,937
Issuance of stock	141,342	143,750	(2,408)
Preferred stock redemption	(842,500)	(842,500)	3,830	(3,830)
Subordinated debt converted to preferred stock	79,966	93,568	(13,602)
Net activity under employee plans and related tax benefits	6,463		6,463
Net activity under employee plans and related tax benefits (in shares)			(17,866)
Dividends on preferred stock	(72,614)	28,095		(100,709)
Dividends on common stock, $0.02 per share	(3,704)			(3,704)
Change in deferred compensation	360			360
Other changes in noncontrolling interests	18					18
Balance at Jun. 30, 2012	$ 6,489,363	$ 1,800,473	$ 4,157,525	$ 1,110,120	$ (576,147)	$ (2,608)
Balance (in shares) at Jun. 30, 2012	184,117,522		184,117,522