Goodwill and Intangible Assets - Goodwill Attributable to Each Business Segments (Detail) - USD ($) $ in Millions	7 Months Ended	12 Months Ended
	Jun. 30, 2016	Dec. 31, 2016	Dec. 31, 2015
Goodwill [Roll Forward]
Goodwill, Beginning Balance		$ 14,480	$ 13,978
Goodwill, Acquired During Period		54	508
Other adjustments		(15)	(6)
Goodwill, Ending Balance		14,519	14,480
Commercial Banking
Goodwill [Roll Forward]
Goodwill, Beginning Balance		4,883	4,384
Goodwill, Acquired During Period		18	500
Other adjustments		0	(1)
Goodwill, Ending Balance		4,901	4,883
Credit Card
Goodwill [Roll Forward]
Goodwill, Beginning Balance		4,997	5,001
Goodwill, Acquired During Period		36	1
Other adjustments		(15)	(5)
Goodwill, Ending Balance		5,018	4,997
Consumer Banking
Goodwill [Roll Forward]
Goodwill, Beginning Balance		4,600	4,593
Goodwill, Acquired During Period		0	7
Other adjustments		0	0
Goodwill, Ending Balance		$ 4,600	$ 4,600
GE Healthcare [Member]
Goodwill [Roll Forward]
Goodwill, Acquired During Period	$ 518