Deposits and Borrowings - Schedule of Components of Interest Expense on Short-Term Borrowings and Long-Term Debt (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Short-term borrowings:
Federal funds purchased and securities loaned or sold under agreements to repurchase	$ 0	$ 0	$ 1	$ 1
FHLB advances	6	6	15	22
Total short-term borrowings	6	6	16	23
Long-term debt:
Securitized debt obligations	32	42	109	143
Senior and subordinated notes	71	76	226	240
Other long-term borrowings	10	5	20	17
Total long-term debt	113	123	355	400
Total interest expense	$ 119	$ 129	$ 371	$ 423