Derivative Instruments And Hedging Activities (Narrative) (Details) - USD ($)		3 Months Ended
		Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015
Derivative [Line Items]
Derivative Instruments, Gain (Loss) Recognized in Other Comprehensive Income (Loss), Effective Portion, Net		$ 20,696,000	$ 4,253,000
Derivative Instruments in Hedges, Net Investment in Foreign Operations, Assets, Fair Value		0
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net		2,997,000	1,016,000
Fair values of derivative assets reduced (increased) by net credit valuation adjustments		5,100,000	3,300,000
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Future Expected		7,700,000
Total derivatives, Notional amount		5,291,198,000		$ 5,147,068,000
Cash collateral pledged for derivative liabilities		86,000,000
Additional collateral that would be required to be pledge if credit rating was downgraded by one notch		1,900,000
Derivative Instrument, Noninterest Income (Expense)		1,962,000	3,253,000
Derivatives Designated As Hedging Instrument Offset To Interest Expense		$ 0	468,000
Cash Flow Hedging [Member]
Derivative [Line Items]
Derivative Instrument, Noninterest Income (Expense)	[1]
Derivatives Designated As Hedging Instruments [Member]
Derivative [Line Items]
Derivative Instruments, Gain (Loss) Recognized in Other Comprehensive Income (Loss), Effective Portion, Net		$ 20,696,000	4,253,000
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net		2,997,000	1,016,000
Total derivatives, Notional amount		$ 1,387,500,000		1,387,500,000
Derivative Instrument, Noninterest Income (Expense)
Derivatives Designated As Hedging Instrument Offset To Interest Expense		$ 0	468,000
Derivatives Designated As Hedging Instruments [Member] | Cash Flow Hedging [Member]
Derivative [Line Items]
Derivative Instruments, Gain (Loss) Recognized in Other Comprehensive Income (Loss), Effective Portion, Net	[1]	20,696,000	4,253,000
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	[1]	2,997,000	1,016,000
Derivatives Designated As Hedging Instruments [Member] | Cash Flow Hedging [Member] | Interest Rate Swaps [Member]
Derivative [Line Items]
Derivative Instruments, Gain (Loss) Recognized in Other Comprehensive Income (Loss), Effective Portion, Net		20,696,000	4,253,000
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	[1]	2,997,000	1,016,000
Total derivatives, Notional amount		1,387,500,000		1,387,500,000
Derivatives Designated As Hedging Instruments [Member] | Fair Value Hedging [Member] | Terminated Swaps On Long Term Debt [Member]
Derivative [Line Items]
Derivatives Designated As Hedging Instrument Offset To Interest Expense		0	468,000
Derivatives Not Designated As Hedging Instruments [Member]
Derivative [Line Items]
Total derivatives, Notional amount		3,903,698,000		3,759,568,000
Derivative Instrument, Noninterest Income (Expense)		1,962,000	3,253,000
Derivatives Not Designated As Hedging Instruments [Member] | Interest Rate Swaps [Member]
Derivative [Line Items]
Total derivatives, Notional amount		103,989,000		40,314,000
Derivative Instrument, Noninterest Income (Expense)		235,000
Derivatives Not Designated As Hedging Instruments [Member] | Interest Rate Swaps For Customers [Member]
Derivative [Line Items]
Total derivatives, Notional amount		3,449,818,000		3,256,190,000
Derivative Instrument, Noninterest Income (Expense)		(509,000)	517,000
Derivatives Not Designated As Hedging Instruments [Member] | Future [Member]
Derivative [Line Items]
Derivative Instrument, Noninterest Income (Expense)		0	1,000
Derivatives Not Designated As Hedging Instruments [Member] | Foreign Exchange [Member]
Derivative [Line Items]
Total derivatives, Notional amount		349,891,000		463,064,000
Derivative Instrument, Noninterest Income (Expense)		2,236,000	$ 2,735,000
Other Liabilities [Member]
Derivative [Line Items]
Derivative Liability, Fair Value, Gross Liability		104,469,000		72,568,000
Other Liabilities [Member] | Derivatives Designated As Hedging Instruments [Member]
Derivative [Line Items]
Derivative Liability, Fair Value, Gross Liability		0		956,000
Other Liabilities [Member] | Derivatives Designated As Hedging Instruments [Member] | Cash Flow Hedging [Member] | Interest Rate Swaps [Member]
Derivative [Line Items]
Derivative Liability, Fair Value, Gross Liability		0		956,000
Other Liabilities [Member] | Derivatives Not Designated As Hedging Instruments [Member]
Derivative [Line Items]
Derivative Liability, Fair Value, Gross Liability		104,469,000		71,612,000
Other Liabilities [Member] | Derivatives Not Designated As Hedging Instruments [Member] | Interest Rate Swaps [Member]
Derivative [Line Items]
Derivative Liability, Fair Value, Gross Liability		250,000		8,000
Other Liabilities [Member] | Derivatives Not Designated As Hedging Instruments [Member] | Interest Rate Swaps For Customers [Member]
Derivative [Line Items]
Derivative Liability, Fair Value, Gross Liability		89,771,000		53,843,000
Other Liabilities [Member] | Derivatives Not Designated As Hedging Instruments [Member] | Foreign Exchange [Member]
Derivative [Line Items]
Derivative Liability, Fair Value, Gross Liability		14,448,000		17,761,000
Other Liabilities [Member] | Derivative Financial Instruments, Liabilities [Member]
Derivative [Line Items]
Gross amounts recognized		$ 104,469,000		$ 72,568,000

[1] Amounts recognized in OCI and reclassified from AOCI represent the effective portion of the change in fair value of the derivative.