Changes in Accumulated Other Comprehensive (Loss) Income (Details 1) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other non-interest revenue	$ 483	$ 504	$ 1,514	$ 1,493
Interest expense on long-term debt and other	280	274	841	886
Other expenses	1,498	1,635	3,388	4,569
(Decrease) increase due to amounts reclassified into earnings	1			2
Net Unrealized Gains (Losses) on Investment Securities [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other non-interest revenue	1
Income tax provision for other non-interest revenue	0
(Decrease) increase due to amounts reclassified into earnings	(1)	(1)	(3)	(1)
Foreign Currency Translation Adjustments [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
(Decrease) increase due to amounts reclassified into earnings	0	0	0	(1)
Accumulated Other Comprehensive Loss [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
(Decrease) increase due to amounts reclassified into earnings	1	1	3	2
Reclassification out of accumulated other comprehensive income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
(Decrease) increase due to amounts reclassified into earnings		1	3
Reclassification out of accumulated other comprehensive income [Member] | Net Unrealized Gains (Losses) on Investment Securities [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other non-interest revenue	1	1	5	1
Income tax provision for other non-interest revenue	0	0	(2)	0
(Decrease) increase due to amounts reclassified into earnings	1	1	3	1
Reclassification out of accumulated other comprehensive income [Member] | Foreign Currency Translation Adjustments [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Income tax benefit for other, net expense	0	0	0	0
Other, net expense, net of taxes	0	0	0	1
(Decrease) increase due to amounts reclassified into earnings	$ 0	$ 0	$ 0	$ 1