Equity, Changes in Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014
Changes in Accumulated Other Comprehensive Income (Loss), By Component
Beginning balance, accumulated other comprehensive income (loss), net of tax	$ 20,677
Ending balance, accumulated other comprehensive income (loss), net of tax	21,453
Accumulated Other Comprehensive Income (Loss) [Member]
Changes in Accumulated Other Comprehensive Income (Loss), By Component
Beginning balance, accumulated other comprehensive income (loss), net of tax	(367)	$ 350
Other comprehensive income (loss) before reclassifications	(169)	78
Amounts reclassified from accumulated other comprehensive income (loss)	7	(2)
Other comprehensive income (loss)	(162)	76
Ending balance, accumulated other comprehensive income (loss), net of tax	(529)	426
Foreign Currency Translation Adjustment [Member]
Changes in Accumulated Other Comprehensive Income (Loss), By Component
Beginning balance, accumulated other comprehensive income (loss), net of tax	1	408
Other comprehensive income (loss) before reclassifications	(169)	76
Amounts reclassified from accumulated other comprehensive income (loss)	0	0
Other comprehensive income (loss)	(169)	76
Ending balance, accumulated other comprehensive income (loss), net of tax	(168)	484
Defined Benefit Plans Items [Member]
Changes in Accumulated Other Comprehensive Income (Loss), By Component
Beginning balance, accumulated other comprehensive income (loss), net of tax	(368)	(58)
Other comprehensive income (loss) before reclassifications	0	0
Amounts reclassified from accumulated other comprehensive income (loss)	7	0
Other comprehensive income (loss)	7	0
Ending balance, accumulated other comprehensive income (loss), net of tax	(361)	(58)
Gains and (Losses) on Cash Flow Hedges [Member]
Changes in Accumulated Other Comprehensive Income (Loss), By Component
Beginning balance, accumulated other comprehensive income (loss), net of tax	0	0
Other comprehensive income (loss) before reclassifications	0	2
Amounts reclassified from accumulated other comprehensive income (loss)	0	(2)
Other comprehensive income (loss)	0	0
Ending balance, accumulated other comprehensive income (loss), net of tax	$ 0	$ 0