Loan Securitization (Carrying Values And Classification Of The Restricted Assets And Liabilities Relating To The Securitization Activities) (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Jun. 30, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Dec. 31, 2010
Restricted Assets And Liabilities Relating To The Securitization [Line Items]
Interest-bearing deposits with banks-restricted for securitization investors	$ 0		$ 272,592	$ 37,165
Allowance for loan losses	(112,287)	(111,920)	(110,381)	(118,649)	(117,362)	(113,903)
Net loans-restricted for securitization investors	0		411,532	643,466
Secured borrowings-owed to securitization investors	0	360,800	600,000	600,000
Restricted Assets And Liabilities [Member]
Restricted Assets And Liabilities Relating To The Securitization [Line Items]
Cash collateral	1,795		4,427	1,759
Collections and interest funding accounts	0		268,165	35,406
Interest-bearing deposits with banks-restricted for securitization investors	1,795		272,592	37,165
Loans, net of unearned income-restricted for securitization investors	0		412,988	645,621
Allowance for loan losses	0		(1,456)	(2,155)
Net loans-restricted for securitization investors	0		411,532	643,466
Other assets	0		2,319	2,568
Total assets	1,795		686,443	683,199
Secured borrowings-owed to securitization investors	0		600,000	600,000
Other liabilities	0		2,821	4,490
Total liabilities	$ 0		$ 602,821	$ 604,490