Fair Value (Schedule Of Assets And Liabilities Measured At Fair Value On A Recurring Basis Using Level 3 Inputs) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total net gains (losses) included in, Other noninterest expense	$ 286,099	$ 275,767	$ 226,934
Municipal Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of assets and liabilities, Beginning balance	22,289	64,314
Total net gains (losses) included in, Accretion of purchase discount included in interest on securities available-for-sale	237
Total net gains (losses) included in, Fixed income securities gains (losses), net	37	4,157
Total net gains (losses) included in, Other comprehensive income (loss)	(1,762)	(1,157)
Total net gains (losses) included in, Sales	(895)
Total net gains (losses) included in, Redemptions and paydowns	(2,525)
Total net gains (losses) included in, Purchases, sales, issuances, and settlements, net		(45,025)
Fair value of assets and liabilities, Ending balance	17,381	22,289
Trust Preferred - Banks And Insurance [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of assets and liabilities, Beginning balance	1,241,694	1,359,444
Total net gains (losses) included in, Accretion of purchase discount included in interest on securities available-for-sale	5,057
Total net gains (losses) included in, Fixed income securities gains (losses), net	19,972	2,369
Total net gains (losses) included in, Net impairment losses on investment securities	(27,480)	(68,002)
Total net gains (losses) included in, Other comprehensive income (loss)	(161,012)	(41,933)
Total net gains (losses) included in, Sales	(72,881)
Total net gains (losses) included in, Redemptions and paydowns	(75,994)
Total net gains (losses) included in, Purchases, sales, issuances, and settlements, net		(10,184)
Fair value of assets and liabilities, Ending balance	929,356	1,241,694
Trust Preferred Securities - REIT [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of assets and liabilities, Beginning balance	19,165	24,018
Total net gains (losses) included in, Fixed income securities gains (losses), net	(3,605)
Total net gains (losses) included in, Net impairment losses on investment securities	(1,285)	(10,628)
Total net gains (losses) included in, Other comprehensive income (loss)	4,908	5,725
Total net gains (losses) included in, Sales	(538)
Total net gains (losses) included in, Purchases, sales, issuances, and settlements, net		50
Fair value of assets and liabilities, Ending balance	18,645	19,165
Auction Rate [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of assets and liabilities, Beginning balance	109,609	159,440
Total net gains (losses) included in, Accretion of purchase discount included in interest on securities available-for-sale	11
Total net gains (losses) included in, Fixed income securities gains (losses), net	1,941	3,815
Total net gains (losses) included in, Other comprehensive income (loss)	(381)	(603)
Total net gains (losses) included in, Sales	(135)
Total net gains (losses) included in, Redemptions and paydowns	(41,025)
Total net gains (losses) included in, Purchases, sales, issuances, and settlements, net		(53,043)
Fair value of assets and liabilities, Ending balance	70,020	109,609
Other Asset-Backed [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of assets and liabilities, Beginning balance	69,630	62,430
Total net gains (losses) included in, Accretion of purchase discount included in interest on securities available-for-sale	196
Total net gains (losses) included in, Fixed income securities gains (losses), net	(6,918)	358
Total net gains (losses) included in, Net impairment losses on investment securities	(4,150)	(6,773)
Total net gains (losses) included in, Other comprehensive income (loss)	8,799	27,501
Total net gains (losses) included in, Sales	(19,310)
Total net gains (losses) included in, Redemptions and paydowns	(4,701)
Total net gains (losses) included in, Purchases, sales, issuances, and settlements, net		(13,886)
Fair value of assets and liabilities, Ending balance	43,546	69,630
Private Equity Investments [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of assets and liabilities, Beginning balance	141,690	158,941
Total net gains (losses) included in, Dividends and other investment income	9,630	6,856
Total net gains (losses) included in, Equity securities gains (losses), net	(3,085)	(6,388)
Total net gains (losses) included in, Purchases	21,172
Total net gains (losses) included in, Sales	(22,397)
Total net gains (losses) included in, Redemptions and paydowns	(18,662)
Total net gains (losses) included in, Purchases, sales, issuances, and settlements, net		(17,719)
Fair value of assets and liabilities, Ending balance	128,348	141,690
Derivatives [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of assets and liabilities, Beginning balance	(15,925)
Total net gains (losses) included in, Fair value and non hedge derivative loss		(22,795)
Total net gains (losses) included in, Redemptions and paydowns	10,503
Total net gains (losses) included in, Purchases, sales, issuances, and settlements, net		6,870
Fair value of assets and liabilities, Ending balance		(15,925)
Fair value of liabilities, Ending balance	(5,422)
Other Liabilities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of assets and liabilities, Beginning balance	(561)	(522)
Total net gains (losses) included in, Other noninterest expense	475	(39)
Fair value of assets and liabilities, Ending balance		(561)
Fair value of liabilities, Ending balance	$ (86)