Derivatives (Derivatives Associated With Interest Rate Risk Management Activities) (Details) (USD $) In Thousands						3 Months Ended				9 Months Ended						3 Months Ended				9 Months Ended				3 Months Ended				9 Months Ended				3 Months Ended				9 Months Ended
	Sep. 30, 2011	Dec. 31, 2010	Sep. 30, 2010	Sep. 30, 2011 Customer Interest Rate Contracts [Member]	Sep. 30, 2010 Customer Interest Rate Contracts [Member]	Sep. 30, 2011 Customer Interest Rate Contracts [Member] Customer Interest Rate Contracts Hedging [Member] Hedging Instruments And Hedged Items [Member]		Sep. 30, 2010 Customer Interest Rate Contracts [Member] Customer Interest Rate Contracts Hedging [Member] Hedging Instruments And Hedged Items [Member]		Sep. 30, 2011 Customer Interest Rate Contracts [Member] Customer Interest Rate Contracts Hedging [Member] Hedging Instruments And Hedged Items [Member]		Sep. 30, 2010 Customer Interest Rate Contracts [Member] Customer Interest Rate Contracts Hedging [Member] Hedging Instruments And Hedged Items [Member]		Sep. 30, 2011 Offsetting Upstream Interest Rate Contracts [Member]	Sep. 30, 2010 Offsetting Upstream Interest Rate Contracts [Member]	Sep. 30, 2011 Offsetting Upstream Interest Rate Contracts [Member] Customer Interest Rate Contracts Hedging [Member] Hedging Instruments And Hedged Items [Member]		Sep. 30, 2010 Offsetting Upstream Interest Rate Contracts [Member] Customer Interest Rate Contracts Hedging [Member] Hedging Instruments And Hedged Items [Member]		Sep. 30, 2011 Offsetting Upstream Interest Rate Contracts [Member] Customer Interest Rate Contracts Hedging [Member] Hedging Instruments And Hedged Items [Member]		Sep. 30, 2010 Offsetting Upstream Interest Rate Contracts [Member] Customer Interest Rate Contracts Hedging [Member] Hedging Instruments And Hedged Items [Member]		Sep. 30, 2011 Interest Rate Swaps [Member] Debt Hedging [Member] Hedging Instruments [Member]		Sep. 30, 2010 Interest Rate Swaps [Member] Debt Hedging [Member] Hedging Instruments [Member]		Sep. 30, 2011 Interest Rate Swaps [Member] Debt Hedging [Member] Hedging Instruments [Member]		Sep. 30, 2010 Interest Rate Swaps [Member] Debt Hedging [Member] Hedging Instruments [Member]		Sep. 30, 2011 Term Borrowings [Member] Debt Hedging [Member] Hedged Items [Member]		Sep. 30, 2010 Term Borrowings [Member] Debt Hedging [Member] Hedged Items [Member]		Sep. 30, 2011 Term Borrowings [Member] Debt Hedging [Member] Hedged Items [Member]		Sep. 30, 2010 Term Borrowings [Member] Debt Hedging [Member] Hedged Items [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Notional				$ 1,438,750	$ 1,684,689	$ 1,048,686	[1]	$ 1,167,907	[1]	$ 1,048,686	[1]	$ 1,167,907	[1]	$ 1,438,750	$ 1,684,689	$ 1,048,686	[1]	$ 1,167,907	[1]	$ 1,048,686	[1]	$ 1,167,907	[1]	$ 1,604,000	[2]	$ 1,104,000	[2]	$ 1,604,000	[2]	$ 1,104,000	[2]
Assets				120,529	106,042	77,297	[1]	97,040	[1]	77,297	[1]	97,040	[1]	1,521	5,342	514	[1]	368	[1]	514	[1]	368	[1]	137,786	[2]	129,664	[2]	137,786	[2]	129,664	[2]
Liabilities				1,521	5,342	514	[1]	368	[1]	514	[1]	368	[1]	120,529	106,043	79,797	[1]	101,837	[1]	79,797	[1]	101,837	[1]
Gains/(Losses)						11,532	[1]	8,386	[1]	4,636	[1]	31,730	[1]			(11,923)	[1]	(8,584)	[1]	(4,929)	[1]	(33,028)	[1]	36,748	[2]	13,249	[2]	40,110	[2]	52,678	[2]
Term borrowings	2,509,804	3,228,070	2,805,731																													1,604,000	[2],[3]	1,104,000	[2],[3]	1,604,000	[2],[3]	1,104,000	[2],[3]
Gains/(Losses) related to term borrowings																																$ (36,748)	[2],[4]	$ (13,249)	[2],[4]	$ (40,110)	[2],[4]	$ (52,678)	[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 long term debt 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.