Derivatives (Derivatives Associated With Interest Rate Risk Management Activities) (Details) (USD $) In Thousands, unless otherwise specified						3 Months Ended				6 Months Ended						3 Months Ended				6 Months Ended				3 Months Ended				6 Months Ended				3 Months Ended				6 Months Ended
	Jun. 30, 2013	Dec. 31, 2012	Jun. 30, 2012	Jun. 30, 2013 Customer Interest Rate Contracts [Member]	Jun. 30, 2012 Customer Interest Rate Contracts [Member]	Jun. 30, 2013 Customer Interest Rate Contracts [Member] Customer Interest Rate Contracts Hedging [Member] Hedging Instruments And Hedged Items [Member]		Jun. 30, 2012 Customer Interest Rate Contracts [Member] Customer Interest Rate Contracts Hedging [Member] Hedging Instruments And Hedged Items [Member]		Jun. 30, 2013 Customer Interest Rate Contracts [Member] Customer Interest Rate Contracts Hedging [Member] Hedging Instruments And Hedged Items [Member]		Jun. 30, 2012 Customer Interest Rate Contracts [Member] Customer Interest Rate Contracts Hedging [Member] Hedging Instruments And Hedged Items [Member]		Jun. 30, 2013 Offsetting Upstream Interest Rate Contracts [Member]	Jun. 30, 2012 Offsetting Upstream Interest Rate Contracts [Member]	Jun. 30, 2013 Offsetting Upstream Interest Rate Contracts [Member] Customer Interest Rate Contracts Hedging [Member] Hedging Instruments And Hedged Items [Member]		Jun. 30, 2012 Offsetting Upstream Interest Rate Contracts [Member] Customer Interest Rate Contracts Hedging [Member] Hedging Instruments And Hedged Items [Member]		Jun. 30, 2013 Offsetting Upstream Interest Rate Contracts [Member] Customer Interest Rate Contracts Hedging [Member] Hedging Instruments And Hedged Items [Member]		Jun. 30, 2012 Offsetting Upstream Interest Rate Contracts [Member] Customer Interest Rate Contracts Hedging [Member] Hedging Instruments And Hedged Items [Member]		Jun. 30, 2013 Interest Rate Swap [Member] Debt [Member] Hedging Instruments [Member]		Jun. 30, 2012 Interest Rate Swap [Member] Debt [Member] Hedging Instruments [Member]		Jun. 30, 2013 Interest Rate Swap [Member] Debt [Member] Hedging Instruments [Member]		Jun. 30, 2012 Interest Rate Swap [Member] Debt [Member] Hedging Instruments [Member]		Jun. 30, 2013 Long Term Debt [Member] Debt [Member] Hedged Items [Member]		Jun. 30, 2012 Long Term Debt [Member] Debt [Member] Hedged Items [Member]		Jun. 30, 2013 Long Term Debt [Member] Debt [Member] Hedged Items [Member]		Jun. 30, 2012 Long Term Debt [Member] Debt [Member] Hedged Items [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Notional				$ 1,706,209	$ 1,502,164	$ 890,611	[1]	$ 994,512	[1]	$ 890,611	[1]	$ 994,512	[1]	$ 1,706,209	$ 1,502,164	$ 890,611	[1]	$ 994,512	[1]	$ 890,611	[1]	$ 994,512	[1]	$ 1,254,000	[2]	$ 1,604,000	[2]	$ 1,254,000	[2]	$ 1,604,000	[2]
Assets				88,851	130,705	36,742	[1]	65,982	[1]	36,742	[1]	65,982	[1]	8,925	1,498	3,027	[1]	389	[1]	3,027	[1]	389	[1]	71,606	[2]	114,854	[2]	71,606	[2]	114,854	[2]
Liabilities				8,925	1,498	3,027	[1]	389	[1]	3,027	[1]	389	[1]	88,851	130,705	37,242	[1]	67,482	[1]	37,242	[1]	67,482	[1]	18,722	[2]	1,104	[2]	18,722	[2]	1,104	[2]
Gains/(Losses)						(15,896)	[1]	2,206	[1]	(21,209)	[1]	(3,583)	[1]			16,196	[1]	(2,006)	[1]	21,909	[1]	4,183	[1]	(24,774)	[2]	(2,931)	[2]	(42,348)	[2]	(13,161)	[2]
Term borrowings	1,800,255	2,226,482	2,294,224																													1,254,000	[2],[3]	1,604,000	[2],[3]	1,254,000	[2],[3]	1,604,000	[2],[3]
Gains/(Losses) related to term borrowings																																$ 24,774	[2],[4]	$ 2,931	[2],[4]	$ 42,348	[2],[4]	$ 13,161	[2],[4]

[1] Gains/losses included in the Other expense section of the Consolidated Condensed Statements of Income.

[2] Gains/losses included in the All other income and commissions section of the Consolidated Condensed Statements of Income.

[3] Represents par value of term borrowings being hedged.

[4] Represents gains and losses attributable to changes in fair value due to interest rate risk as designated in ASC 815-20 hedging relationships.