Reconciliation of Net Income to Net Income Available to Common Shareholders (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	3 Months Ended			9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016		Sep. 30, 2017		Sep. 30, 2016
Document Period End Date				Sep. 30, 2017
Net Income (Loss) Attributable to Parent	$ 538	$ 474	[1]	$ 1,533		$ 1,413	[2]
Dividends, Preferred Stock, Cash	(26)	(17)		(65)	[3]	(49)	[3]
Undistributed Earnings (Loss) Allocated to Participating Securities, Basic	0	0		0		(1)
Net Income (Loss) Available to Common Stockholders, Basic	$ 512	$ 457		$ 1,468		$ 1,363
Average basic common shares	478,258	496,304		483,711		501,036
Stock options	1,000	2,000		1,000		2,000
Restricted stock	5,000	3,000		4,000		3,000
Weighted Average Number of Shares Outstanding, Diluted	483,640	500,885		489,176		505,619
Net income/(loss) per average common share - diluted	$ 1.06	$ 0.91		$ 3.00		$ 2.70
Earnings Per Share, Basic	$ 1.07	$ 0.92		$ 3.04		$ 2.72

[1] Beginning in the second quarter of 2017, the Company realigned its business segment structure from three segments to two segments. Specifically, the Company retained the previous composition of the Wholesale Banking segment and changed the basis of presentation of the Consumer Banking and Private Wealth Management segment and Mortgage Banking segment such that those segments were combined into a single Consumer segment. Accordingly, business segment information presented for the three months ended September 30, 2016 has been revised to conform to the new business segment structure and updated internal funds transfer pricing methodology for consistent presentation.

[2] Beginning in the second quarter of 2017, the Company realigned its business segment structure from three segments to two segments. Specifically, the Company retained the previous composition of the Wholesale Banking segment and changed the basis of presentation of the Consumer Banking and Private Wealth Management segment and Mortgage Banking segment such that those segments were combined into a single Consumer segment. Accordingly, business segment information presented for the nine months ended September 30, 2016 has been revised to conform to the new business segment structure and updated internal funds transfer pricing methodology for consistent presentation.

[3] For the nine months ended September 30, 2017, dividends were $3,044 per share for both Perpetual Preferred Stock Series A and B, $4,406 per share for Perpetual Preferred Stock Series E, $4,219 per share for Perpetual Preferred Stock Series F, and $2,090 per share for Perpetual Preferred Stock Series G.For the nine months ended September 30, 2016, dividends were $3,056 per share for both Perpetual Preferred Stock Series A and B, $4,406 per share for Perpetual Preferred Stock Series E, and $4,219 per share for Perpetual Preferred Stock Series F.