Intangible Assets - Additional Information (Detail) (USD $)	1 Months Ended	3 Months Ended		6 Months Ended
	Mar. 31, 2012	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2012
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Service fees				$ 46,800,000,000
Residential mortgage banking revenue service fees		21,000,000	22,000,000	42,000,000	47,000,000
Commercial mortgage servicing rights		12,000,000		12,000,000		11,000,000
Purchased from HSBC FInance account of credit card	746,000,000
Credit card receivables not being sold to Capital One at a fair value	108,000,000
Fair value of Intangible asset related to account relationships purchased include in branch sale	43,000,000
Fair value of Intangible asset related to account relationships purchased retained	$ 65,000,000
Useful life	10 years