Mortgage Servicing Rights - Additional Information (Detail) (USD $)	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013
Transfers And Servicing Of Financial Assets [Abstract]
Residential mortgage loans serviced for others including subserviced mortgages with no corresponding MSRs asset	$ 227,200,000,000		$ 226,800,000,000
Gain/Loss on the fair value of mortgage servicing rights and fair value changes of derivatives used to offset MSR	58,000,000	41,000,000
Loan servicing fees	$ 188,000,000	$ 187,000,000