Reportable Operating Segements and Geographic Operations (Details 1) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Segment Revenues And Pretax Income Loss By Geographic Location [Line Items]
Total revenues net of interest expense	$ 8,391	$ 8,193	$ 8,284	$ 7,950	$ 9,081	$ 8,303	$ 8,631	$ 8,173	$ 32,818	$ 34,188	$ 32,870
Pretax income	$ 1,454	$ 1,938	$ 2,230	$ 2,316	$ 2,225	$ 2,246	$ 2,312	$ 2,208	7,938	8,991	7,888
United States Geographic Region [Member]
Segment Revenues And Pretax Income Loss By Geographic Location [Line Items]
Total revenues net of interest expense									24,791	24,751	23,641
Pretax income									8,010	8,869	7,679
EMEA Geographic Region [Member]
Segment Revenues And Pretax Income Loss By Geographic Location [Line Items]
Total revenues net of interest expense									3,161	3,767	3,700
Pretax income									534	525	524
JAPA Geographic Region [Member]
Segment Revenues And Pretax Income Loss By Geographic Location [Line Items]
Total revenues net of interest expense									2,649	2,934	2,952
Pretax income									456	463	488
LACC Geographic Region [Member]
Segment Revenues And Pretax Income Loss By Geographic Location [Line Items]
Total revenues net of interest expense									2,384	2,888	2,900
Pretax income									658	683	701
Other Unallocated [Member]
Segment Revenues And Pretax Income Loss By Geographic Location [Line Items]
Total revenues net of interest expense									(167)	(152)	(323)
Pretax income									$ (1,720)	$ (1,549)	$ (1,504)