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, 2012	Dec. 31, 2011	Jun. 30, 2011	Jun. 30, 2012 Customer Interest Rate Contracts [Member]	Jun. 30, 2011 Customer Interest Rate Contracts [Member]	Jun. 30, 2012 Customer Interest Rate Contracts [Member] Customer Interest Rate Contracts Hedging [Member] Hedging Instruments And Hedged Items [Member]		Jun. 30, 2011 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, 2011 Customer 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]	Jun. 30, 2011 Offsetting Upstream Interest Rate Contracts [Member]	Jun. 30, 2012 Offsetting Upstream Interest Rate Contracts [Member] Customer Interest Rate Contracts Hedging [Member] Hedging Instruments And Hedged Items [Member]		Jun. 30, 2011 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, 2011 Offsetting Upstream Interest Rate Contracts [Member] Customer Interest Rate Contracts Hedging [Member] Hedging Instruments And Hedged Items [Member]		Jun. 30, 2012 Interest Rate Swaps [Member] Debt Hedging [Member] Hedging Instruments [Member]		Jun. 30, 2011 Interest Rate Swaps [Member] Debt Hedging [Member] Hedging Instruments [Member]		Jun. 30, 2012 Interest Rate Swaps [Member] Debt Hedging [Member] Hedging Instruments [Member]		Jun. 30, 2011 Interest Rate Swaps [Member] Debt Hedging [Member] Hedging Instruments [Member]		Jun. 30, 2012 Term Borrowings [Member] Debt Hedging [Member] Hedged Items [Member]		Jun. 30, 2011 Term Borrowings [Member] Debt Hedging [Member] Hedged Items [Member]		Jun. 30, 2012 Term Borrowings [Member] Debt Hedging [Member] Hedged Items [Member]		Jun. 30, 2011 Term Borrowings [Member] Debt Hedging [Member] Hedged Items [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Notional				$ 1,502,164	$ 1,458,306	$ 994,512	[1]	$ 980,417	[1]	$ 994,512	[1]	$ 980,417	[1]	$ 1,502,164	$ 1,458,306	$ 994,512	[1]	$ 980,417	[1]	$ 994,512	[1]	$ 980,417	[1]	$ 1,604,000	[2]	$ 1,604,000	[2]	$ 1,604,000	[2]	$ 1,604,000	[2]
Assets				130,705	72,576	65,982	[1]	65,074	[1]	65,982	[1]	65,074	[1]	1,498	1,537	389	[1]	414	[1]	389	[1]	414	[1]	114,854	[2]	113,090	[2]	114,854	[2]	113,090	[2]
Liabilities				1,498	1,537	389	[1]	414	[1]	389	[1]	414	[1]	130,705	72,576	67,482	[1]	67,774	[1]	67,482	[1]	67,774	[1]	1,104	[2]	12,023	[2]	1,104	[2]	12,023	[2]
Gains/(Losses)						2,206	[1]	3,996	[1]	(3,583)	[1]	(6,894)	[1]			(2,006)	[1]	(4,596)	[1]	4,183	[1]	6,994	[1]	(2,931)	[2]	22,789	[2]	(13,161)	[2]	3,362	[2]
Term borrowings	2,294,224	2,481,660	2,502,517																													1,604,000	[2],[3]	1,604,000	[2],[3]	1,604,000	[2],[3]	1,604,000	[2],[3]
Gains/(Losses) related to term borrowings																																$ 2,931	[2],[4]	$ (22,789)	[2],[4]	$ 13,161	[2],[4]	$ (3,362)	[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.