Loans - Impaired Commercial Loans Considered as TDR Loans (Detail) (Commercial Loan [Member], USD $) In Millions, unless otherwise specified	Mar. 31, 2014		Dec. 31, 2013
Financing Receivable, Impaired [Line Items]
Amount with Impairment Reserves	$ 76		$ 165
Amount without Impairment Reserves	233		316
Total Impaired Commercial Loans	309	[1],[2]	481	[1],[2]
Impairment Reserve	14		40
Construction and Other Real Estate [Member]
Financing Receivable, Impaired [Line Items]
Amount with Impairment Reserves	56		122
Amount without Impairment Reserves	204		211
Total Impaired Commercial Loans	260	[1],[2]	333	[1],[2]
Impairment Reserve	9		32
Business and Corporate Banking [Member]
Financing Receivable, Impaired [Line Items]
Amount with Impairment Reserves	19		28
Amount without Impairment Reserves	10		12
Total Impaired Commercial Loans	29	[1],[2]	40	[1],[2]
Impairment Reserve	4		3
Global Banking [Member]
Financing Receivable, Impaired [Line Items]
Amount with Impairment Reserves	0		14
Amount without Impairment Reserves	0		51
Total Impaired Commercial Loans	0	[1],[2]	65	[1],[2]
Impairment Reserve	0		5
Other Commercial [Member]
Financing Receivable, Impaired [Line Items]
Amount with Impairment Reserves	1		1
Amount without Impairment Reserves	19		42
Total Impaired Commercial Loans	20	[1],[2]	43	[1],[2]
Impairment Reserve	$ 1		$ 0

[1] The impaired commercial loan balances included in the table above reflect the current carrying amount of the loan and includes all basis adjustments, such as partial charge-offs, unamortized deferred fees and costs on originated loans and any premiums or discounts. The following table reflects the unpaid principal balance of impaired commercial loans included in the table above:March 31, 2014 December 31, 2013 (in millions)Construction and other real estate$289 $380Business and corporate banking71 91Global banking— 123Other commercial20 47Total$380 $641

[2] Includes impaired commercial loans that are also considered TDR Loans which totaled $263 million and $389 million at March 31, 2014 and December 31, 2013, respectively.