Revisions - Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	3 Months Ended			9 Months Ended
	Sep. 30, 2015	Mar. 31, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net income	$ 3,979	$ 3,515	$ 2,739	$ 11,425	$ 9,461
Comprehensive Income (Loss), Net of Tax, Attributable to Parent	$ 3,316	3,117	2,155	$ 9,806	9,254
As Previously Reported
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net income		3,586	2,813		9,687
Comprehensive Income (Loss), Net of Tax, Attributable to Parent		3,188	2,229		9,480
Adjustment
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net income		(71)	(74)		(226)
Comprehensive Income (Loss), Net of Tax, Attributable to Parent		$ (71)	$ (74)		$ (226)