Fair Value Of Assets And Liabilities (Schedule Of Assets And Liabilities Measured At Fair Value On A Recurring Basis) (Details) - USD ($)	Mar. 31, 2016		Dec. 31, 2015	Mar. 31, 2015
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	$ 1,226,521,000		$ 881,450,000	$ 1,532,463,000
Loans held-for-sale	26,287,000			26,700,000
Securities available for sale, Fair Value	4,014,405,000	[1]	$ 3,929,846,000	3,672,331,000	[2]
Total other assets	196,595,000			176,935,000
Total assets	5,301,955,000			5,252,661,000
Total other liabilities	146,297,000			133,273,000
Total liabilities	884,950,000			946,414,000
Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Securities available for sale, Fair Value	3,852,552,000			3,516,563,000
Level 1
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Loans held-for-sale	0			0
Securities available for sale, Fair Value	25,309,000			25,870,000
Total other assets	43,888,000			33,350,000
Total assets	69,197,000			59,220,000
Total other liabilities	13,229,000			7,828,000
Total liabilities	13,229,000			7,828,000
Level 2
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Loans held-for-sale	0			0
Securities available for sale, Fair Value	3,825,743,000			3,487,502,000
Total other assets	150,982,000			141,243,000
Total assets	5,200,189,000			5,155,882,000
Total other liabilities	128,448,000			120,440,000
Total liabilities	867,101,000			933,581,000
Level 3
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Loans held-for-sale	26,287,000			26,700,000
Securities available for sale, Fair Value	1,500,000			3,191,000
Total other assets	1,725,000			2,342,000
Total assets	32,569,000			37,559,000
Total other liabilities	4,620,000			5,005,000
Total liabilities	4,620,000			5,005,000
U.S. treasuries
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Securities available for sale, Fair Value	100,000			100,000
U.S. treasuries | Level 1
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Securities available for sale, Fair Value	0			0
U.S. treasuries | Level 2
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Securities available for sale, Fair Value	100,000			100,000
U.S. treasuries | Level 3
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Securities available for sale, Fair Value	0			0
Government Agency Issued Mortgage-Backed Securities ("MBS")
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Securities available for sale, Fair Value	1,887,422,000			762,850,000
Government Agency Issued Mortgage-Backed Securities ("MBS") | Level 1
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Securities available for sale, Fair Value	0			0
Government Agency Issued Mortgage-Backed Securities ("MBS") | Level 2
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Securities available for sale, Fair Value	1,887,422,000			762,850,000
Government Agency Issued Mortgage-Backed Securities ("MBS") | Level 3
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Securities available for sale, Fair Value	0			0
Government Agency Issued Collateralized Mortgage Obligations ("CMO")
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Securities available for sale, Fair Value	1,938,221,000			2,716,147,000
Government Agency Issued Collateralized Mortgage Obligations ("CMO") | Level 1
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Securities available for sale, Fair Value	0			0
Government Agency Issued Collateralized Mortgage Obligations ("CMO") | Level 2
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Securities available for sale, Fair Value	1,938,221,000			2,716,147,000
Government Agency Issued Collateralized Mortgage Obligations ("CMO") | Level 3
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Securities available for sale, Fair Value	0			0
Other U.S. Government Agencies
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Securities available for sale, Fair Value	0			1,691,000
Other U.S. Government Agencies | Level 1
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Securities available for sale, Fair Value	0			0
Other U.S. Government Agencies | Level 2
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Securities available for sale, Fair Value	0			0
Other U.S. Government Agencies | Level 3
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Securities available for sale, Fair Value	0			1,691,000
States And Municipalities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Securities available for sale, Fair Value	1,500,000			9,905,000
States And Municipalities | Level 1
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Securities available for sale, Fair Value	0			0
States And Municipalities | Level 2
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Securities available for sale, Fair Value	0			8,405,000
States And Municipalities | Level 3
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Securities available for sale, Fair Value	1,500,000			1,500,000
Equity, Mutual Funds, And Other
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Securities available for sale, Fair Value	25,309,000			25,870,000
Equity, Mutual Funds, And Other | Level 1
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Securities available for sale, Fair Value	25,309,000			25,870,000
Equity, Mutual Funds, And Other | Level 2
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Securities available for sale, Fair Value	0			0
Equity, Mutual Funds, And Other | Level 3
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Securities available for sale, Fair Value	0			0
Mortgage Servicing Rights
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other assets	1,725,000			2,342,000
Mortgage Servicing Rights | Level 1
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other assets	0			0
Mortgage Servicing Rights | Level 2
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other assets	0			0
Mortgage Servicing Rights | Level 3
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other assets	1,725,000			2,342,000
Deferred Compensation Assets
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other assets	29,863,000			26,440,000
Deferred Compensation Assets | Level 1
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other assets	29,863,000			26,440,000
Deferred Compensation Assets | Level 2
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other assets	0			0
Deferred Compensation Assets | Level 3
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other assets	0			0
Derivatives, Forwards And Futures
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other assets	14,025,000			6,910,000
Total other liabilities	13,229,000			7,828,000
Derivatives, Forwards And Futures | Level 1
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other assets	14,025,000			6,910,000
Total other liabilities	13,229,000			7,828,000
Derivatives, Forwards And Futures | Level 2
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other assets	0			0
Total other liabilities	0			0
Derivatives, Forwards And Futures | Level 3
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other assets	0			0
Total other liabilities	0			0
Derivatives, Interest Rate Contracts
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other assets	150,982,000			140,976,000
Total other liabilities	128,448,000			120,440,000
Derivatives, Interest Rate Contracts | Level 1
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other assets	0			0
Total other liabilities	0			0
Derivatives, Interest Rate Contracts | Level 2
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other assets	150,982,000			140,976,000
Total other liabilities	128,448,000			120,440,000
Derivatives, Interest Rate Contracts | Level 3
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other assets	0			0
Total other liabilities	0			0
Derivatives, Other
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other assets	0			267,000
Total other liabilities	4,620,000			5,005,000
Derivatives, Other | Level 1
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other assets	0			0
Total other liabilities	0			0
Derivatives, Other | Level 2
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other assets	0			267,000
Total other liabilities	0			0
Derivatives, Other | Level 3
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other assets	0			0
Total other liabilities	4,620,000			5,005,000
Fixed Income
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	1,223,469,000			1,527,142,000
Total trading liabilities - fixed income	738,653,000			813,141,000
Fixed Income | Level 1
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	0			0
Total trading liabilities - fixed income	0			0
Fixed Income | Level 2
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	1,223,464,000			1,527,137,000
Total trading liabilities - fixed income	738,653,000			813,141,000
Fixed Income | Level 3
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	5,000			5,000
Total trading liabilities - fixed income	0			0
Fixed Income | U.S. treasuries
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	63,687,000			108,199,000
Total trading liabilities - fixed income	512,799,000			514,886,000
Fixed Income | U.S. treasuries | Level 1
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	0			0
Total trading liabilities - fixed income	0			0
Fixed Income | U.S. treasuries | Level 2
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	63,687,000			108,199,000
Total trading liabilities - fixed income	512,799,000			514,886,000
Fixed Income | U.S. treasuries | Level 3
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	0			0
Total trading liabilities - fixed income	0			0
Fixed Income | Government Agency Issued Mortgage-Backed Securities ("MBS")
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	427,851,000			547,569,000
Fixed Income | Government Agency Issued Mortgage-Backed Securities ("MBS") | Level 1
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	0			0
Fixed Income | Government Agency Issued Mortgage-Backed Securities ("MBS") | Level 2
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	427,851,000			547,569,000
Fixed Income | Government Agency Issued Mortgage-Backed Securities ("MBS") | Level 3
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	0			0
Fixed Income | Government Agency Issued Collateralized Mortgage Obligations ("CMO")
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	169,254,000			312,086,000
Total trading liabilities - fixed income	17,000			1,000
Fixed Income | Government Agency Issued Collateralized Mortgage Obligations ("CMO") | Level 1
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	0			0
Total trading liabilities - fixed income	0			0
Fixed Income | Government Agency Issued Collateralized Mortgage Obligations ("CMO") | Level 2
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	169,254,000			312,086,000
Total trading liabilities - fixed income	17,000			1,000
Fixed Income | Government Agency Issued Collateralized Mortgage Obligations ("CMO") | Level 3
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	0			0
Total trading liabilities - fixed income	0			0
Fixed Income | Other U.S. Government Agencies
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	201,760,000			161,317,000
Total trading liabilities - fixed income	5,037,000			17,863,000
Fixed Income | Other U.S. Government Agencies | Level 1
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	0			0
Total trading liabilities - fixed income	0			0
Fixed Income | Other U.S. Government Agencies | Level 2
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	201,760,000			161,317,000
Total trading liabilities - fixed income	5,037,000			17,863,000
Fixed Income | Other U.S. Government Agencies | Level 3
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	0			0
Total trading liabilities - fixed income	0			0
Fixed Income | States And Municipalities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	49,745,000			57,181,000
Total trading liabilities - fixed income				1,643,000
Fixed Income | States And Municipalities | Level 1
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	0			0
Total trading liabilities - fixed income				0
Fixed Income | States And Municipalities | Level 2
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	49,745,000			57,181,000
Total trading liabilities - fixed income				1,643,000
Fixed Income | States And Municipalities | Level 3
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	0			0
Total trading liabilities - fixed income				0
Fixed Income | Trading Loans
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	21,992,000
Fixed Income | Trading Loans | Level 1
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	0
Fixed Income | Trading Loans | Level 2
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	21,992,000
Fixed Income | Trading Loans | Level 3
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	0
Fixed Income | Corporate And Other Debt
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	284,581,000			339,565,000
Total trading liabilities - fixed income	220,800,000			276,748,000
Fixed Income | Corporate And Other Debt | Level 1
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	0			0
Total trading liabilities - fixed income	0			0
Fixed Income | Corporate And Other Debt | Level 2
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	284,576,000			339,560,000
Total trading liabilities - fixed income	220,800,000			276,748,000
Fixed Income | Corporate And Other Debt | Level 3
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	5,000			5,000
Total trading liabilities - fixed income	0			0
Fixed Income | Equity, Mutual Funds, And Other
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	4,599,000			1,225,000
Total trading liabilities - fixed income				2,000,000
Fixed Income | Equity, Mutual Funds, And Other | Level 1
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	0			0
Total trading liabilities - fixed income				0
Fixed Income | Equity, Mutual Funds, And Other | Level 2
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	4,599,000			1,225,000
Total trading liabilities - fixed income				2,000,000
Fixed Income | Equity, Mutual Funds, And Other | Level 3
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	0			0
Total trading liabilities - fixed income				0
Mortgage Banking
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	3,052,000			5,321,000
Mortgage Banking | Level 1
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	0			0
Mortgage Banking | Level 2
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	0			0
Mortgage Banking | Level 3
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	$ 3,052,000			$ 5,321,000

[1] Includes $ 3 .1 billion of securities pledged to secure public deposits, securities sold under agreements to repurchase, and for other purposes.

[2] Includes $ 3.2 billion of securities pledged to secure public deposits, securities sold under agreements to repu rchase, and for other purposes .