Fair Value (Schedule Of Assets And Liabilities Measured At Fair Value By Class On A Recurring Basis Using Level 3 Inputs) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2014
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total net gains (losses) included in, Other noninterest expense	$ 53,347	$ 66,941	$ 111,778	$ 139,615
Municipal Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of assets, Beginning balance	2,465	10,184	4,164	10,662
Total net gains (losses) included in, Accretion of purchase discount on securities available-for-sale	1	8	3	18
Total net gains (losses) included in, Fixed income securities gains (losses), net	(375)		(344)	16
Total net gains (losses) included in, Other comprehensive income (loss)	560	92	687	(182)
Total net gains (losses) included in, Sales	$ 2,651		2,651
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Settlements		(246)	(1,859)	(476)
Fair value of assets, Ending balance	$ 0	10,038	0	10,038
Banks, Trust and Insurance, Equities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of assets, Beginning balance	438,338	690,217	393,007	1,238,820
Total net gains (losses) included in, Accretion of purchase discount on securities available-for-sale	214	633	471	1,353
Total net gains (losses) included in, Fixed income securities gains (losses), net	(136,368)	4,383	(136,691)	22,965
Total net gains (losses) included in, Other noninterest expense			57,308
Total net gains (losses) included in, Other comprehensive income (loss)	148,496	$ 6,878	141,547	101,340
Total net gains (losses) included in, Sales	437,442		440,055	546,388
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Settlements	(13,238)	$ (16,306)	(15,587)	(63,092)
Fair value of assets, Ending balance	0	$ 685,805	0	685,805
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers out of Level 3				69,193
Fair Value, Assets Measured On Recurring Basis, And Gain (Loss) Included In Net Impairment Losses On Investment Securities
Trust Preferred Securities - Real Estate Investment Trusts [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of assets, Beginning balance		$ 0		$ 22,996
Total net gains (losses) included in, Accretion of purchase discount on securities available-for-sale
Total net gains (losses) included in, Fixed income securities gains (losses), net				$ 1,399
Total net gains (losses) included in, Other comprehensive income (loss)
Total net gains (losses) included in, Sales
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Settlements				$ 24,395
Fair value of assets, Ending balance		$ 0		0
Fair Value, Assets Measured On Recurring Basis, And Gain (Loss) Included In Net Impairment Losses On Investment Securities
Auction Rate Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of assets, Beginning balance		$ 6,560		6,599
Total net gains (losses) included in, Accretion of purchase discount on securities available-for-sale		$ 1		2
Total net gains (losses) included in, Fixed income securities gains (losses), net
Total net gains (losses) included in, Other comprehensive income (loss)		$ 17		(23)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Settlements
Fair value of assets, Ending balance		$ 6,578		6,578
Other Asset-Backed [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of assets, Beginning balance	$ 4,803	$ 30	4,761	$ 25,800
Total net gains (losses) included in, Accretion of purchase discount on securities available-for-sale
Total net gains (losses) included in, Fixed income securities gains (losses), net	$ (606)		(606)	$ 10,917
Total net gains (losses) included in, Other comprehensive income (loss)	(116)		(74)	(15)
Total net gains (losses) included in, Sales	$ 4,081		$ 4,081	36,669
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Settlements		$ (2)		(5)
Fair value of assets, Ending balance	$ 0	$ 28	$ 0	28
Fair Value, Assets Measured On Recurring Basis, And Gain (Loss) Included In Net Impairment Losses On Investment Securities
Private Equity Investments [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of assets, Beginning balance	105,232	$ 81,052	97,649	82,410
Total net gains (losses) included in, Dividends and other investment income	(1,633)	(1,052)	(559)	(2,747)
Total net gains (losses) included in, Equity securities gains, net	714	584	3,967	584
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Purchases	7,262	7,104	12,314	8,460
Total net gains (losses) included in, Sales	(991)	(15)	(2,508)	(839)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Settlements	(469)	(5,417)	(748)	(5,612)
Fair value of assets, Ending balance	110,115	82,256	110,115	82,256
Servicing Contracts [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of liabilities, Beginning balance	12,001	11,207	12,227	8,852
Total net gains (losses) included in, Fixed income securities gains (losses), net			1,487
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Noninterest Income	1,483	45		526
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Purchases	210	379	381	2,456
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Settlements	(192)	(170)	(593)	(373)
Fair value of liabilities, Ending balance	13,502	11,461	13,502	11,461
Derivatives [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of liabilities, Beginning balance	$ 0	(5,632)	(13)	(4,303)
Derivative, Gain (Loss) on Derivative, Net		(467)		(7,894)
Total net gains (losses) included in, Other noninterest expense		101		109
Total net gains (losses) included in, Purchases		5,866		11,956
Fair value of liabilities, Ending balance	$ 0	$ (132)	0	$ (132)
Fair Value, Assets Measured On Recurring Basis, And Gain (Loss) Included In Net Impairment Losses On Investment Securities			13
Estimate of Fair Value Measurement [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other Liabilities, Fair Value Disclosure					$ 13
Other Postretirement Benefits, Individual Contracts, Type of Deferred Compensation [Domain] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other Assets, Fair Value Disclosure	89,729		89,729		88,878
Other Liabilities, Fair Value Disclosure	89,729		89,729		88,878
Other Postretirement Benefits, Individual Contracts, Type of Deferred Compensation [Domain] | Estimate of Fair Value Measurement [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other Assets, Fair Value Disclosure	89,729		89,729		88,878
Other Liabilities, Fair Value Disclosure	$ 89,729		$ 89,729		$ 88,878