Commitments, Contingencies, and Guarantees (Details) (USD $)	12 Months Ended
	Dec. 31, 2012
Credit Commitments
Total Credit Commitments	$ 2,075,456,000
Current residential mortgage loans serviced for investors as percentage of total	99.00%
Unfunded Commitments to Extend Credit
Credit Commitments
Total Credit Commitments	1,999,542,000
Standby Letters of Credit
Credit Commitments
Total Credit Commitments	62,043,000
Assets secured for standby letters of credit	28,200,000
Commercial Letters of Credit
Credit Commitments
Total Credit Commitments	13,871,000
Standby and Commercial Letteres of Credit [Member] | Minimum
Credit Commitments
Standby and commercial letters of credit, remaining term (in months)	1 month
Standby and Commercial Letteres of Credit [Member] | Maximum
Credit Commitments
Standby and commercial letters of credit, remaining term (in months)	16 months
Residential Mortgage
Credit Commitments
Unpaid principal balance of mortgage loans sold	2,900,000,000
Number of mortgage loans repurchased	7
Unpaid principal balance of repurchased mortgage loan	$ 2,200,000
Number of mortgage loans repurchased, delinquent	4