Changes in Accumulated Other Comprehensive Income (Details 1) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other non-interest revenue	$ 1,732	$ 2,029	$ 2,033
Other expense	(5,776)	(5,162)	$ (6,793)
Increase (decrease) due to amounts reclassified into earnings	7	2
Net Unrealized Investment Gains (Losses) on Investment Securities [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other non-interest revenue	0	9
Income tax provision for other non-interest revenue	0	(3)
Other non-interest revenue, net of taxes	0	6
Foreign Currency Translation Adjustments [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other expense	(7)	(4)
Income tax benefit for other, net expense	14	0
Other, net expense, net of taxes	$ 7	$ (4)