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, 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
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss) for the period	110,387			110,723		(336)
Other comprehensive income	39,254				39,254
Stock Issued During Period, Value, New Issues	168,751	171,827	3,076
Subordinated debt converted to preferred stock	991	1,160	(169)
Net activity under employee plans and related tax benefits, shares			47,273
Net activity under employee plans and related tax benefits	7,438		7,438
Dividends on preferred stock	(22,399)			(22,399)
Dividends on common stock	(1,833)			(1,833)
Change in deferred compensation	(175)			(175)
Other changes in noncontrolling interests	(402)		586			(988)
Balance at Mar. 31, 2013	6,350,653	1,301,289	4,170,888	1,290,131	(406,903)	(4,752)
Balance (in shares) at Mar. 31, 2013			184,246,471
Balance at Dec. 31, 2013	6,464,563	1,003,970	4,179,024	1,473,670	(192,101)	0
Balance (in shares) at Dec. 31, 2013	184,677,696		184,677,696
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss) for the period	101,210			101,210		0
Other comprehensive income	46,639				46,639
Subordinated debt converted to preferred stock	0
Net activity under employee plans and related tax benefits, shares			217,486
Net activity under employee plans and related tax benefits	6,489		6,489
Dividends on preferred stock	(25,020)			(25,020)
Dividends on common stock	(7,436)			(7,436)
Change in deferred compensation	(229)			(229)
Balance at Mar. 31, 2014	$ 6,586,216	$ 1,003,970	$ 4,185,513	$ 1,542,195	$ (145,462)	$ 0
Balance (in shares) at Mar. 31, 2014	184,895,182		184,895,182