Equity, Changes in Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2015	Sep. 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	21,321
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 loss before reclassifications	(439)	(199)
Amounts reclassified from accumulated other comprehensive income (loss)	11	(2)
Other comprehensive income (loss)	(428)	(201)
Ending balance, accumulated other comprehensive income (loss), net of tax	(795)	149
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 loss before reclassifications	(439)	(198)
Amounts reclassified from accumulated other comprehensive income (loss)	0	0
Other comprehensive income (loss)	(439)	(198)
Ending balance, accumulated other comprehensive income (loss), net of tax	(438)	210
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 loss before reclassifications	0	0
Amounts reclassified from accumulated other comprehensive income (loss)	11	(3)
Other comprehensive income (loss)	11	(3)
Ending balance, accumulated other comprehensive income (loss), net of tax	(357)	(61)
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 loss before reclassifications	0	(1)
Amounts reclassified from accumulated other comprehensive income (loss)	0	1
Other comprehensive income (loss)	0	0
Ending balance, accumulated other comprehensive income (loss), net of tax	$ 0	$ 0