Derivative Instruments And Hedging Activities (Schedule Of Notional Amounts And Recorded Gross Fair Values And Related Gain (Loss) Of Derivative Instruments) (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2016		Dec. 31, 2015
Derivative [Line Items]
Total derivatives, Notional amount		$ 6,209,146		$ 5,147,068
Derivatives hedging instruments, liabilities		59,200
Amount of derivative gain (loss), recognized in OCI		7,912		12,124
Amount of derivative gain (loss), Reclassified from AOCI to interest income		11,290		9,004
Derivatives instruments, Noninterest income (expense)		25,744		16,959
Derivatives designated as hedging instruments, Offset to interest expense		0		1,504
Other Assets [Member]
Derivative [Line Items]
Derivatives hedging instruments, assets		64,195		77,638
Other Liabilities [Member]
Derivative [Line Items]
Derivatives hedging instruments, liabilities		59,221		72,568
Derivatives Designated As Hedging Instruments [Member]
Derivative [Line Items]
Total derivatives, Notional amount		1,387,500		1,387,500
Amount of derivative gain (loss), recognized in OCI		7,912		12,124
Amount of derivative gain (loss), Reclassified from AOCI to interest income		11,290		9,004
Derivatives designated as hedging instruments, Offset to interest expense		0		1,504
Derivatives Designated As Hedging Instruments [Member] | Cash Flow Hedges [Member]
Derivative [Line Items]
Amount of derivative gain (loss), recognized in OCI		7,912		12,124
Amount of derivative gain (loss), Reclassified from AOCI to interest income		11,290		9,004	[1]
Derivatives Designated As Hedging Instruments [Member] | Other Assets [Member]
Derivative [Line Items]
Derivatives hedging instruments, assets		2,289		5,461
Derivatives Designated As Hedging Instruments [Member] | Other Liabilities [Member]
Derivative [Line Items]
Derivatives hedging instruments, liabilities		1,148		956
Derivatives Designated As Hedging Instruments [Member] | Interest Rate Swaps [Member] | Cash Flow Hedges [Member]
Derivative [Line Items]
Total derivatives, Notional amount	[2]	1,387,500		1,387,500
Amount of derivative gain (loss), recognized in OCI		7,912	[2]	12,124
Amount of derivative gain (loss), Reclassified from AOCI to interest income		11,290	[2]	9,004
Derivatives Designated As Hedging Instruments [Member] | Interest Rate Swaps [Member] | Other Assets [Member] | Cash Flow Hedges [Member]
Derivative [Line Items]
Derivatives hedging instruments, assets	[2]	2,289		5,461
Derivatives Designated As Hedging Instruments [Member] | Interest Rate Swaps [Member] | Other Liabilities [Member] | Cash Flow Hedges [Member]
Derivative [Line Items]
Derivatives hedging instruments, liabilities	[2]	1,148		956
Derivatives Designated As Hedging Instruments [Member] | Terminated Swaps On Long-Term Debt [Member] | Fair Value Hedges [Member]
Derivative [Line Items]
Derivatives designated as hedging instruments, Offset to interest expense		0		1,504
Derivatives Not Designated As Hedging Instruments [Member]
Derivative [Line Items]
Total derivatives, Notional amount		4,821,646		3,759,568
Derivatives instruments, Noninterest income (expense)		25,744		16,959
Derivatives Not Designated As Hedging Instruments [Member] | Other Assets [Member]
Derivative [Line Items]
Derivatives hedging instruments, assets		61,906		72,177
Derivatives Not Designated As Hedging Instruments [Member] | Other Liabilities [Member]
Derivative [Line Items]
Derivatives hedging instruments, liabilities		58,073		71,612
Derivatives Not Designated As Hedging Instruments [Member] | Interest Rate Swaps [Member]
Derivative [Line Items]
Total derivatives, Notional amount		235,167		40,314
Derivatives instruments, Noninterest income (expense)		1,096		0
Derivatives Not Designated As Hedging Instruments [Member] | Interest Rate Swaps [Member] | Other Assets [Member]
Derivative [Line Items]
Derivatives hedging instruments, assets		1,876		0
Derivatives Not Designated As Hedging Instruments [Member] | Interest Rate Swaps [Member] | Other Liabilities [Member]
Derivative [Line Items]
Derivatives hedging instruments, liabilities		351		8
Derivatives Not Designated As Hedging Instruments [Member] | Interest Rate Swaps For Customers [Member]
Derivative [Line Items]
Total derivatives, Notional amount	[3]	4,162,264		3,256,190
Derivatives instruments, Noninterest income (expense)		13,952	[3]	7,438
Derivatives Not Designated As Hedging Instruments [Member] | Interest Rate Swaps For Customers [Member] | Other Assets [Member]
Derivative [Line Items]
Derivatives hedging instruments, assets	[3]	48,754		51,353
Derivatives Not Designated As Hedging Instruments [Member] | Interest Rate Swaps For Customers [Member] | Other Liabilities [Member]
Derivative [Line Items]
Derivatives hedging instruments, liabilities	[3]	49,050		53,843
Derivatives Not Designated As Hedging Instruments [Member] | Options Held [Member]
Derivative [Line Items]
Total derivatives, Notional amount		424,215		463,064
Derivatives Not Designated As Hedging Instruments [Member] | Options Held [Member] | Other Assets [Member]
Derivative [Line Items]
Derivatives hedging instruments, assets		11,276		20,824
Derivatives Not Designated As Hedging Instruments [Member] | Options Held [Member] | Other Liabilities [Member]
Derivative [Line Items]
Derivatives hedging instruments, liabilities		8,672		17,761
Derivatives Not Designated As Hedging Instruments [Member] | Futures Contracts [Member]
Derivative [Line Items]
Derivatives instruments, Noninterest income (expense)		0		2
Derivatives Not Designated As Hedging Instruments [Member] | Foreign Exchange [Member]
Derivative [Line Items]
Derivatives instruments, Noninterest income (expense)		$ 10,696		$ 9,519

[1] Amounts of $11.3 million for 2016 and $9.0 million for 2015 are the amounts of reclassification to earnings presented in the tabular changes of AOCI in Note 13.

[2] Note: These schedules are not intended to present at any given time the Company’s long/short position with respect to its derivative contracts.1 Amounts recognized in OCI and reclassified from AOCI represent the effective portion of the derivative gain (loss).

[3] Amounts include both the customer swaps and the offsetting derivative contracts.