Fair Value Of Assets And Liabilities (Schedule Of Assets And Liabilities Measured At Fair Value On A Recurring Basis) (Details) - USD ($)	Sep. 30, 2015		Dec. 31, 2014	Sep. 30, 2014
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	$ 1,229,180,000		$ 1,194,391,000	$ 1,338,022,000
Loans held-for-sale	26,789,000			31,443,000
Securities available for sale	3,673,641,000	[1]	$ 3,556,613,000	3,534,671,000	[2]
Total other assets	180,513,000			165,523,000
Total assets	4,954,410,000			4,913,852,000
Total other liabilities	140,965,000			123,442,000
Total liabilities	929,528,000			655,676,000
Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Securities available for sale	3,517,928,000			3,378,864,000
Level 1
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Loans held-for-sale	0			0
Securities available for sale	25,840,000			26,080,000
Total other assets	42,307,000			28,082,000
Total assets	68,147,000			54,162,000
Total other liabilities	15,921,000			2,895,000
Total liabilities	15,921,000			2,895,000
Level 2
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Loans held-for-sale	0			0
Securities available for sale	3,489,142,000			3,349,355,000
Total other assets	136,213,000			134,561,000
Total assets	4,849,932,000			4,815,815,000
Total other liabilities	120,234,000			112,907,000
Total liabilities	908,797,000			645,141,000
Level 3
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Loans held-for-sale	26,789,000			31,443,000
Securities available for sale	2,946,000			3,429,000
Total other assets	1,993,000			2,880,000
Total assets	36,331,000			43,875,000
Total other liabilities	4,810,000			7,640,000
Total liabilities	4,810,000			7,640,000
U.S. treasuries
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Securities available for sale	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	0			0
U.S. treasuries | Level 2
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Securities available for sale	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	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	945,951,000			716,865,000
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	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	945,951,000			716,865,000
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	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	2,535,436,000			2,623,685,000
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	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	2,535,436,000			2,623,685,000
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	0			0
Other U.S. Government Agencies
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Securities available for sale	1,446,000			1,929,000
Other U.S. Government Agencies | Level 1
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Securities available for sale	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	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	1,446,000			1,929,000
States And Municipalities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Securities available for sale	9,155,000			10,205,000
States And Municipalities | Level 1
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Securities available for sale	0			0
States And Municipalities | Level 2
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Securities available for sale	7,655,000			8,705,000
States And Municipalities | Level 3
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Securities available for sale	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	25,840,000			26,080,000
Equity, Mutual Funds, And Other | Level 1
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Securities available for sale	25,840,000			26,080,000
Equity, Mutual Funds, And Other | Level 2
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Securities available for sale	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	0			0
Mortgage Servicing Rights
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other assets	1,993,000			2,880,000
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	1,993,000			2,880,000
Deferred Compensation Assets
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other assets	25,972,000			24,901,000
Deferred Compensation Assets | Level 1
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other assets	25,972,000			24,901,000
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	16,335,000			3,181,000
Total other liabilities	15,921,000			2,895,000
Derivatives, Forwards And Futures | Level 1
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other assets	16,335,000			3,181,000
Total other liabilities	15,921,000			2,895,000
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	136,121,000			134,561,000
Total other liabilities	120,234,000			112,907,000
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	136,121,000			134,561,000
Total other liabilities	120,234,000			112,907,000
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	92,000
Total other liabilities	4,810,000			7,640,000
Derivatives, Other | Level 1
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other assets	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	92,000
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
Total other liabilities	4,810,000			7,640,000
Fixed Income
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	1,224,582,000			1,331,904,000
Total trading liabilities - fixed income	788,563,000			532,234,000
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	1,224,577,000			1,331,899,000
Total trading liabilities - fixed income	788,563,000			532,234,000
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	97,211,000			247,796,000
Total trading liabilities - fixed income	478,759,000			278,306,000
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	97,211,000			247,796,000
Total trading liabilities - fixed income	478,759,000			278,306,000
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	265,290,000			301,559,000
Total trading liabilities - fixed income	1,481,000
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
Total trading liabilities - fixed income	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	265,290,000			301,559,000
Total trading liabilities - fixed income	1,481,000
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
Total trading liabilities - fixed income	0
Fixed Income | Government Agency Issued Collateralized Mortgage Obligations ("CMO")
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	283,927,000			201,016,000
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
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	283,927,000			201,016,000
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
Fixed Income | Other U.S. Government Agencies
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	113,739,000			108,874,000
Total trading liabilities - fixed income	6,482,000			4,964,000
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	113,739,000			108,874,000
Total trading liabilities - fixed income	6,482,000			4,964,000
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	65,255,000			42,900,000
Total trading liabilities - fixed income				543,000
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	65,255,000			42,900,000
Total trading liabilities - fixed income				543,000
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	16,943,000
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	16,943,000
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	381,475,000			379,773,000
Total trading liabilities - fixed income	301,841,000			248,421,000
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	381,470,000			379,768,000
Total trading liabilities - fixed income	301,841,000			248,421,000
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	742,000			49,986,000
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
Fixed Income | Equity, Mutual Funds, And Other | Level 2
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	742,000			49,986,000
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
Mortgage Banking
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	4,598,000			6,118,000
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	$ 4,598,000			$ 6,118,000

[1] Includes $ 2.9 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 .