Commitments, Contingencies and Guarantees - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2015 USD ($) attorney_general
Commitments and Contingencies Disclosure [Abstract]
Contractual Obligation	$ 1,500,000,000
Other Liabilities Reserve	$ 2,000,000
Loss emergence period	1 year
FDIC civil monetary penalties	$ 3,300,000
Contingency refund	$ 30,000,000
Number of state attorney generals | attorney_general	2