Off-Balance Sheet Arrangements Commitments Guarantees and Contingencies (Narrative) (Detail) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Commitments And Guarantees [Line Items]
Credit card guarantees	$ 8,800,000	$ 7,600,000
Collateralized credit card guarantees	1,000,000	738,000
Minimum percentage of collateral required for securities borrowed	100.00%
Maximum future payments guaranteed	1,800,000,000
Held in trust liquid assets as collateral	1,800,000,000
Rent expense for operating leases	22,700,000	21,600,000	21,600,000
Aggregate future minimum rentals to be received under non-cancelable subleases greater than one year	436,000
Partnership Interest of a Director [Member]
Commitments And Guarantees [Line Items]
Rent expense for operating leases	$ 902,000	$ 898,000	$ 852,000