Reclassifications out of Accumulated Other Comprehensive Income (Details) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Total before tax		$ (1,536)	$ (1,472)	$ (3,208)	$ (2,641)
Tax (expense)/benefit		573	556	1,200	1,001
Net of tax		(963)	(916)	(2,008)	(1,640)
Accumulated Defined Benefit Plans Adjustment [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Actuarial losses	[1],[2]	(1)	0	(2)	(1)
Prior service credits	[1],[2]	0	0	1	1
Total before tax		(1)	0	(1)	0
Tax (expense)/benefit		1	0	1	0
Net of tax		$ 0	$ 0	$ 0	$ 0

[1] Amounts in parenthesis indicate debits to the income statement.

[2] This accumulated other comprehensive income component is included in the computation of net periodic pension cost and retiree health and welfare (see Note 8 for additional details).