Intangible Assets - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	1 Months Ended	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2012
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Residential mortgage banking revenue service fees		$ 21	$ 25
Commercial mortgage servicing rights		12		11
Purchased from HSBC FInance account of credit card	746		746
Credit card receivables not being sold to Capital One at a fair value	108		108
Fair value of Intangible asset related to account relationships purchased include in branch sale	43		43
Fair value of Intangible asset related to account relationships purchased retained	65		65
Other intangible assets are comprised of Favourable lease arrangements		$ 7		$ 8
Useful life	10 years