Fair Value Of Assets And Liabilities (Schedule Of Assets And Liabilities Measured At Fair Value On A Recurring Basis) (Details) - USD ($) $ in Thousands	Jun. 30, 2017		Dec. 31, 2016
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	$ 1,315,891		$ 897,071
Securities available-for-sale	3,949,592	[1]	3,943,499	[2]
Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Loans held-for-sale	22,220		24,269
Securities available-for-sale	3,787,884		3,781,994
Total other assets	126,717		155,479
Total assets	5,252,712		4,858,813
Total other liabilities	92,717		135,897
Total liabilities	648,510		697,745
Level 1 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Loans held-for-sale	0		0
Securities available-for-sale	25,182		25,249
Total other assets	51,113		66,427
Total assets	76,295		91,676
Total other liabilities	12,578		33,274
Total liabilities	12,578		33,274
Level 2 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Loans held-for-sale	1,633		2,345
Securities available-for-sale	3,761,539		3,756,745
Total other assets	75,604		88,067
Total assets	5,152,203		4,741,655
Total other liabilities	74,439		96,378
Total liabilities	630,232		658,226
Level 3 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Loans held-for-sale	20,587		21,924
Securities available-for-sale	1,163		0
Total other assets	0		985
Total assets	24,214		25,482
Total other liabilities	5,700		6,245
Total liabilities	5,700		6,245
Deferred Compensation Assets | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other assets	35,064		32,840
Deferred Compensation Assets | Level 1 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other assets	35,064		32,840
Deferred Compensation Assets | Level 2 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other assets	0		0
Deferred Compensation Assets | Level 3 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other assets	0		0
Mortgage Servicing Rights, Net | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other assets			985
Mortgage Servicing Rights, Net | Level 1 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other assets			0
Mortgage Servicing Rights, Net | Level 2 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other assets			0
Mortgage Servicing Rights, Net | Level 3 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other assets			985
Derivatives, Forwards And Futures | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other assets	16,049		33,587
Total other liabilities	12,578		33,274
Derivatives, Forwards And Futures | Level 1 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other assets	16,049		33,587
Total other liabilities	12,578		33,274
Derivatives, Forwards And Futures | Level 2 | Recurring
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 | Recurring
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 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other assets	75,604		88,025
Total other liabilities	74,389		96,371
Derivatives, Interest Rate Contracts | Level 1 | Recurring
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 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other assets	75,604		88,025
Total other liabilities	74,389		96,371
Derivatives, Interest Rate Contracts | Level 3 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other assets	0		0
Total other liabilities	0		0
Derivatives, Other | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other assets			42
Total other liabilities	5,750		6,252
Derivatives, Other | Level 1 | Recurring
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 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other assets			42
Total other liabilities	50		7
Derivatives, Other | Level 3
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other liabilities	5,700		6,245
Derivatives, Other | Level 3 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other assets			0
Total other liabilities	5,700		6,245
U.S. treasuries | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Securities available-for-sale	100		100
U.S. treasuries | Level 1 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Securities available-for-sale	0		0
U.S. treasuries | Level 2 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Securities available-for-sale	100		100
U.S. treasuries | Level 3 | Recurring
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") | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Securities available-for-sale	2,129,616		2,208,687
Government Agency Issued Mortgage-Backed Securities ("MBS") | Level 1 | Recurring
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 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Securities available-for-sale	2,129,616		2,208,687
Government Agency Issued Mortgage-Backed Securities ("MBS") | Level 3 | Recurring
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") | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Securities available-for-sale	1,631,823		1,547,958
Government Agency Issued Collateralized Mortgage Obligations ("CMO") | Level 1 | Recurring
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 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Securities available-for-sale	1,631,823		1,547,958
Government Agency Issued Collateralized Mortgage Obligations ("CMO") | Level 3 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Securities available-for-sale	0		0
Equity, Mutual Funds, And Other | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Securities available-for-sale	25,182		25,249
Equity, Mutual Funds, And Other | Level 1 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Securities available-for-sale	25,182		25,249
Equity, Mutual Funds, And Other | Level 2 | Recurring
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 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Securities available-for-sale	0		0
SBA - Interest Only Strips | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Securities available-for-sale	1,163
SBA - Interest Only Strips | Level 1 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Securities available-for-sale	0
SBA - Interest Only Strips | Level 2 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Securities available-for-sale	0
SBA - Interest Only Strips | Level 3 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Securities available-for-sale	1,163
Fixed Income | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	1,313,432		894,503
Total trading liabilities - fixed income	555,793		561,848
Fixed Income | Level 1 | Recurring
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 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	1,313,427		894,498
Total trading liabilities - fixed income	555,793		561,848
Fixed Income | Level 3 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	5		5
Total trading liabilities - fixed income	0		0
Fixed Income | U.S. treasuries | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	112,602		146,988
Total trading liabilities - fixed income	380,102		381,229
Fixed Income | U.S. treasuries | Level 1 | Recurring
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 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	112,602		146,988
Total trading liabilities - fixed income	380,102		381,229
Fixed Income | U.S. treasuries | Level 3 | Recurring
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") | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	344,218		256,611
Total trading liabilities - fixed income	212
Fixed Income | Government Agency Issued Mortgage-Backed Securities ("MBS") | Level 1 | Recurring
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 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	344,218		256,611
Total trading liabilities - fixed income	212
Fixed Income | Government Agency Issued Mortgage-Backed Securities ("MBS") | Level 3 | Recurring
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") | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	241,237		150,058
Total trading liabilities - fixed income	2,124
Fixed Income | Government Agency Issued Collateralized Mortgage Obligations ("CMO") | Level 1 | Recurring
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") | Level 2 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	241,237		150,058
Total trading liabilities - fixed income	2,124
Fixed Income | Government Agency Issued Collateralized Mortgage Obligations ("CMO") | Level 3 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	0		0
Total trading liabilities - fixed income	0
Fixed Income | Other U.S. Government Agencies | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	142,596		52,314
Total trading liabilities - fixed income	998		844
Fixed Income | Other U.S. Government Agencies | Level 1 | Recurring
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 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	142,596		52,314
Total trading liabilities - fixed income	998		844
Fixed Income | Other U.S. Government Agencies | Level 3 | Recurring
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 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	56,321		60,351
Total trading liabilities - fixed income	1,178
Fixed Income | States And Municipalities | Level 1 | Recurring
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 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	56,321		60,351
Total trading liabilities - fixed income	1,178
Fixed Income | States And Municipalities | Level 3 | Recurring
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 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	38,716
Fixed Income | Trading Loans | Level 1 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	0
Fixed Income | Trading Loans | Level 2 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	38,716
Fixed Income | Trading Loans | Level 3 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	0
Fixed Income | Corporate And Other Debt | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	376,266		227,939
Total trading liabilities - fixed income	171,179		179,775
Fixed Income | Corporate And Other Debt | Level 1 | Recurring
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 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	376,261		227,934
Total trading liabilities - fixed income	171,179		179,775
Fixed Income | Corporate And Other Debt | Level 3 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	5		5
Total trading liabilities - fixed income	0		0
Fixed Income | Equity, Mutual Funds, And Other | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	1,476		242
Fixed Income | Equity, Mutual Funds, And Other | Level 1 | Recurring
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 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	1,476		242
Fixed Income | Equity, Mutual Funds, And Other | Level 3 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	0		0
Mortgage Banking | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	2,459		2,568
Mortgage Banking | Level 1 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	0		0
Mortgage Banking | Level 2 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	0		0
Mortgage Banking | Level 3 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	$ 2,459		$ 2,568

[1] Includes $3.5 billion of securities pledged to secure public deposits, securities sold under agreements to repurchase, and for other purposes.

[2] Includes $3.3 billion of securities pledged to secure public deposits, securities sold under agreements to repurchase, and for other purposes.