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, 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
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss) for the period	290,464			291,264		(800)
Other comprehensive income	57,346				57,346
Stock Issued During Period, Value, New Issues	141,342	143,750	2,408
Stock Redeemed or Called During Period, Value	(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, shares			21,014
Net activity under employee plans and related tax benefits	11,856		11,856
Dividends on preferred stock	(103,542)	44,696		(148,238)
Dividends on common stock	(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
Balance at Dec. 31, 2012	6,048,641	1,128,302	4,166,109	1,203,815	(446,157)	(3,428)
Balance (in shares) at Dec. 31, 2012	184,199,198		184,199,198
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss) for the period	304,927			305,263		(336)
Other comprehensive income	61,654				61,654
Stock Issued During Period, Value, New Issues	800,000	800,000	(15,627)
Issuance of preferred stock	784,373
Preferred Stock Redemption	(799,468)	(925,748)	580	125,700
Subordinated debt converted to preferred stock	1,210	1,416	(206)
Net activity under employee plans and related tax benefits, shares			400,807
Net activity under employee plans and related tax benefits	26,197		26,197
Dividends on preferred stock	(77,547)			(77,547)
Dividends on common stock	(16,667)			(16,667)
Change in deferred compensation	(109)			(109)
Other changes in noncontrolling interests	(402)		(4,166)			3,764
Balance at Sep. 30, 2013	$ 6,332,809	$ 1,003,970	$ 4,172,887	$ 1,540,455	$ (384,503)	$ 0
Balance (in shares) at Sep. 30, 2013	184,600,005		184,600,005