Reconciliation of Net Income to Net Income Available to Common Shareholders (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017		Dec. 31, 2016
Net Income (Loss) Attributable to Parent		$ 2,775	$ 2,273	[1],[2]	$ 1,878	[3],[4]
Dividends, Preferred Stock, Cash	[5]	(107)	(94)		(66)
Undistributed Earnings (Loss) Allocated to Participating Securities, Basic		0	0		1
Net Income (Loss) Available to Common Stockholders, Basic		$ 2,668	$ 2,179		$ 1,811
Weighted Average Number of Shares Outstanding, Basic		460,922	481,339		498,638
Weighted Average Number of Shares Outstanding, Diluted		464,961	486,954		503,466
Earnings Per Share, Diluted		$ 5.74	$ 4.47		$ 3.60
Earnings Per Share, Basic		$ 5.79	$ 4.53		$ 3.63
Restricted Stock Units (RSUs) [Member]
Dilutive securities		2,900	3,000		2,900
Warrants, options, and restricted stock [Member]
Dilutive securities		1,200	2,700		2,000

[1] During the second quarter of 2018, certain of the Company's business banking clients were transferred from the Wholesale business segment to the Consumer business segment. For all periods prior to the second quarter of 2018, the corresponding financial results have been transferred to the Consumer business segment for comparability purposes.

[2] During the fourth quarter of 2017, the Company sold PAC, the results of which were previously reported within the Wholesale business segment. For all periods prior to January 1, 2018, PAC's financial results, including the gain on sale, have been transferred to Corporate Other for enhanced comparability of the Wholesale business segment excluding PAC.

[3] During the second quarter of 2018, certain of the Company's business banking clients were transferred from the Wholesale business segment to the Consumer business segment. For all periods prior to the second quarter of 2018, the corresponding financial results have been transferred to the Consumer business segment for comparability purposes.

[4] During the fourth quarter of 2017, the Company sold PAC, the results of which were previously reported within the Wholesale business segment. For all periods prior to January 1, 2018, PAC's financial results, including the gain on sale, have been transferred to Corporate Other for enhanced comparability of the Wholesale business segment excluding PAC.

[5] For the year ended December 31, 2018, dividends were $4,056 per share for both Series A and B Preferred Stock, $1,469 per share for Series E Preferred Stock, $5,625 per share for Series F Preferred Stock, $5,050 per share for Series G Preferred Stock, and $5,566 per share for Series H Preferred Stock. For the year ended December 31, 2017, dividends were $4,056 per share for both Series A and B Preferred Stock, $5,875 per share for Series E Preferred Stock, $5,625 per share for Series F Preferred Stock, $3,128 per share for Series G Preferred Stock, and $669 per share for Series H Preferred Stock. For the year ended December 31, 2016, dividends were $4,067 per share for both Series A and B Preferred Stock, $5,875 per share for Series E Preferred Stock, and $5,625 per share for Series F Preferred Stock.