Reportable Operating Segements and Geographic Operations (Details 1) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Segment Revenues And Pretax Income Loss By Geographic Location [Line Items]
Total revenues net of interest expense	$ 8,022	$ 7,774	$ 8,235	$ 8,088	$ 8,391	$ 8,193	$ 8,284	$ 7,950	$ 32,119	$ 32,818	$ 34,188
Pretax income	$ 1,161	$ 1,735	$ 3,016	$ 2,184	$ 1,454	$ 1,938	$ 2,230	$ 2,316	8,096	7,938	8,991
United States Geographic Region [Member]
Segment Revenues And Pretax Income Loss By Geographic Location [Line Items]
Total revenues net of interest expense									24,133	24,927	24,678
Pretax income									8,202	7,500	8,406
EMEA Geographic Region [Member]
Segment Revenues And Pretax Income Loss By Geographic Location [Line Items]
Total revenues net of interest expense									3,248	3,293	3,574
Pretax income									482	544	528
JAPA Geographic Region [Member]
Segment Revenues And Pretax Income Loss By Geographic Location [Line Items]
Total revenues net of interest expense									3,052	2,791	2,923
Pretax income									559	587	565
LACC Geographic Region [Member]
Segment Revenues And Pretax Income Loss By Geographic Location [Line Items]
Total revenues net of interest expense									2,274	2,412	2,784
Pretax income									597	693	675
Other Unallocated [Member]
Segment Revenues And Pretax Income Loss By Geographic Location [Line Items]
Total revenues net of interest expense									(588)	(605)	229
Pretax income									$ (1,744)	$ (1,386)	$ (1,183)