Intangible Assets (Detail) (USD $) In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 167	$ 199
Accumulated Amortization	(152)	(180)
Net Carrying Amount	15us-gaap_FiniteLivedIntangibleAssetsNet	19us-gaap_FiniteLivedIntangibleAssetsNet
Core deposit intangibles
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	122	154
Accumulated Amortization	(112)	(141)
Net Carrying Amount	10	13
Other
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	45	45
Accumulated Amortization	(40)	(39)
Net Carrying Amount	$ 5	$ 6

Accumulated amount of amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 30

-Section 50

-Paragraph 2

-Subparagraph (a)(1)

-URI http://asc.fasb.org/extlink&oid=26713463&loc=d3e16323-109275

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Amount before amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

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Amount after amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

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