Accumulated Other Comprehensive Income (AOCI) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Accumulated other comprehensive income (loss)
Balance of Accumulated Other Comprehensive Income (Loss) at Beginning of Period	$ (1,705)		$ (1,241)
Other comprehensive income (loss) before reclassifications	(155)		(616)
Amounts reclassified from AOCI	(11)		(31)
Other comprehensive income (loss), tax, portion attributable to parent	9		26
Balance of Accumulated Other Comprehensive Income (Loss) at End of period	(1,862)		(1,862)
Other Comprehensive Income (Loss), Net of Tax	(157)		(621)
Foreign Currency Translation Adjustment [Member]
Accumulated other comprehensive income (loss)
Balance of Accumulated Other Comprehensive Income (Loss) at Beginning of Period	(1,152)		(654)
Other comprehensive income (loss) before reclassifications	(146)		(670)
Amounts reclassified from AOCI	(29)		(29)
Other comprehensive income (loss), tax, portion attributable to parent	3		29
Balance of Accumulated Other Comprehensive Income (Loss) at End of period	(1,324)		(1,324)
Other Comprehensive Income (Loss), Net of Tax	(172)		(670)
Deferred Gain (Loss) On Hedging Activities [Member]
Accumulated other comprehensive income (loss)
Balance of Accumulated Other Comprehensive Income (Loss) at Beginning of Period	41	$ (12)	47	$ 5
Other comprehensive income (loss) before reclassifications	(34)	(49)	(3)	(154)
Amounts reclassified from AOCI	(12)	108	(61)	186
Other comprehensive income (loss), tax, portion attributable to parent	13	(23)	25	(13)
Balance of Accumulated Other Comprehensive Income (Loss) at End of period	8	$ 24	8	$ 24
Other Comprehensive Income (Loss), Net of Tax	(33)		(39)
Pension Liability Adjustment [Member]
Accumulated other comprehensive income (loss)
Balance of Accumulated Other Comprehensive Income (Loss) at Beginning of Period	(611)		(630)
Other comprehensive income (loss) before reclassifications	5		14
Amounts reclassified from AOCI	30		59
Other comprehensive income (loss), tax, portion attributable to parent	(8)		(27)
Balance of Accumulated Other Comprehensive Income (Loss) at End of period	(584)		(584)
Other Comprehensive Income (Loss), Net of Tax	27		46
Unrealized Gain (Loss) On Investments [Member]
Accumulated other comprehensive income (loss)
Balance of Accumulated Other Comprehensive Income (Loss) at Beginning of Period	17		(4)
Other comprehensive income (loss) before reclassifications	20		43
Amounts reclassified from AOCI	0		0
Other comprehensive income (loss), tax, portion attributable to parent	1		(1)
Balance of Accumulated Other Comprehensive Income (Loss) at End of period	38		38
Other Comprehensive Income (Loss), Net of Tax	$ 21		$ 42