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	233,919			234,785		(866)
Other comprehensive income (loss)	(127,538)				(127,538)
Issuance of stock	25,048		25,048
Subordinated debt converted to preferred stock	241,152	281,759	(40,607)
Issuance of common stock (in shares)			1,067,540
Net activity under employee plans and related tax benefits	12,637		12,637
Net activity under employee plans and related tax benefits (in shares)			(443,156)
Dividends on preferred stock	(109,723)	16,092		(125,815)
Dividends on common stock, $0.03 per share	(5,478)			(5,478)
Change in deferred compensation	1,604			1,604
Other changes in noncontrolling interests	82					82
Balance at Sep. 30, 2011	6,918,917	2,354,523	4,160,697	994,380	(588,834)	(1,849)
Balance (in shares) at Sep. 30, 2011			184,294,782
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	290,464			291,264		(800)
Other comprehensive income (loss)	57,346				57,346
Issuance of stock	141,342	143,750	(2,408)
Preferred stock redemption	(1,542,500)	(1,542,500)	3,830	(3,830)
Subordinated debt converted to preferred stock	85,352	99,871	(14,519)
Net activity under employee plans and related tax benefits	11,856		11,856
Net activity under employee plans and related tax benefits (in shares)			21,014
Dividends on preferred stock	(103,542)	44,696		(148,238)
Dividends on common stock, $0.03 per share	(5,546)			(5,546)
Change in deferred compensation	237			237
Other changes in noncontrolling interests	18					18
Balance at Sep. 30, 2012	$ 5,918,255	$ 1,123,377	$ 4,162,001	$ 1,170,477	$ (534,738)	$ (2,862)
Balance (in shares) at Sep. 30, 2012	184,156,402		184,156,402