Off-Balance Sheet Arrangements, Guarantees and Other Commitments Summary of Commercial and Standby Letters of Credit (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013		Dec. 31, 2012
Guarantor Obligations [Line Items]
Expires In One Year or Less	$ 911,816
Expires After One Year	64,152
Total Amount Outstanding	975,968	[1]	842,091	[1]
Maximum Amount of Future Payments	975,968
Financial standby letters of credit
Guarantor Obligations [Line Items]
Expires In One Year or Less	845,120
Expires After One Year	52,962
Total Amount Outstanding	898,082
Maximum Amount of Future Payments	898,082
Performance standby letters of credit
Guarantor Obligations [Line Items]
Expires In One Year or Less	58,938
Expires After One Year	11,190
Total Amount Outstanding	70,128
Maximum Amount of Future Payments	70,128
Commercial letters of credit
Guarantor Obligations [Line Items]
Expires In One Year or Less	7,758
Expires After One Year	0
Total Amount Outstanding	7,758
Maximum Amount of Future Payments	$ 7,758

[1] See below for additional information on our commercial and standby letters of credit.