Intangible Assets, Allocation of Goodwill to Operating Segments (Details) - USD ($) $ in Millions	6 Months Ended		12 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016	Dec. 31, 2015
Goodwill [Roll Forward]
Goodwill, Beginning Balance	$ 26,693	$ 25,529	$ 25,529
Reclassification of goodwill held for sale to Other Assets	(96)		0	$ 0
Reduction in goodwill related to divested business and other	(24)	(84)
Goodwill from business combinations		1,518
Goodwill, Ending Balance	26,573	26,963	26,693	25,529
Community Banking [Member]
Goodwill [Roll Forward]
Goodwill, Beginning Balance	16,849	16,849	16,849
Reclassification of goodwill held for sale to Other Assets	0
Reduction in goodwill related to divested business and other	0	0
Goodwill from business combinations		0
Goodwill, Ending Balance	16,849	16,849	16,849	16,849
Wholesale Banking [Member]
Goodwill [Roll Forward]
Goodwill, Beginning Balance	8,585	7,475	7,475
Reclassification of goodwill held for sale to Other Assets	(96)
Reduction in goodwill related to divested business and other	(24)	(84)
Goodwill from business combinations		1,518
Goodwill, Ending Balance	8,465	8,909	8,585	7,475
Wealth and Investment Management [Member]
Goodwill [Roll Forward]
Goodwill, Beginning Balance	1,259	1,205	1,205
Reclassification of goodwill held for sale to Other Assets	0
Reduction in goodwill related to divested business and other	0	0
Goodwill from business combinations		0
Goodwill, Ending Balance	$ 1,259	$ 1,205	$ 1,259	$ 1,205