Restrictions on Cash, Dividends and Other Capital Actions- Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2011
Restricted Cash and Cash Equivalents Items [Line Items]
Banking Subsidiary Reserve Requirement	$ 1,900	$ 1,800
Dividend Received From Nonbank Companies And Related Subsidiaries	$ 1,000	1,100
BHC stress test threshold				$ 50,000
Minimum CET1 Capital Ratio	5.00%
Shares acquired for treasury	$ 850	654	$ 1,320
Proceeds from Issuance of Preferred Stock and Preference Stock		$ 297	1,034
January 22, 2015 ASR
Restricted Cash and Cash Equivalents Items [Line Items]
Shares acquired for treasury	180
April 27, 2015 ASR
Restricted Cash and Cash Equivalents Items [Line Items]
Shares acquired for treasury	155
July 30, 2015 ASR
Restricted Cash and Cash Equivalents Items [Line Items]
Shares acquired for treasury	150
September 4, 2015 ASR
Restricted Cash and Cash Equivalents Items [Line Items]
Shares acquired for treasury	150
December 9, 2015 ASR
Restricted Cash and Cash Equivalents Items [Line Items]
Shares acquired for treasury	$ 215
CCAR authorization
Restricted Cash and Cash Equivalents Items [Line Items]
Common stock dividends restrictions	The potential increase in the quarterly common stock dividend to $0.14 per share in 2016
Stock Repurchase Authorization Amount	$ 765
Preferred stock Series H
Restricted Cash and Cash Equivalents Items [Line Items]
Proceeds from Issuance of Preferred Stock and Preference Stock			$ 593