Noninterest Expense (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Noninterest Expense [Abstract]
Legal (benefit)/expense	$ (317)	$ 2,969	$ 2,883
FDIC-related expense	$ 1,296	$ 1,227	$ 1,037