Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Increase (Decrease) Accumulated Other Comprehensive Loss, Net of Tax
Balance at beginning of the period	$ 171
Other comprehensive income (loss) attributable to the Company	50	$ (220)
Balance at end of the period	299	401
Net Effect of Exchange Rate Fluctuations
Increase (Decrease) Accumulated Other Comprehensive Loss, Net of Tax
Balance at beginning of the period	(568)	(55)
Change before reclassifications	90	(253)
Other comprehensive income (loss) attributable to the Company	90	(253)
Balance at end of the period	(478)	(308)
Change in Certain Derivative Instruments
Increase (Decrease) Accumulated Other Comprehensive Loss, Net of Tax
Balance at beginning of the period	(17)	(11)
Amounts reclassified from accumulated other comprehensive income	(2)
Other comprehensive income (loss) attributable to the Company	(2)
Balance at end of the period	(19)	(11)
Employee Benefit Plans
Increase (Decrease) Accumulated Other Comprehensive Loss, Net of Tax
Balance at beginning of the period	(1,432)	(1,428)
Amounts reclassified from accumulated other comprehensive income	(43)	21
Translation effect	1	15
Tax effect		1
Other comprehensive income (loss) attributable to the Company	(42)	37
Balance at end of the period	(1,474)	(1,391)
Accumulated Other Comprehensive Loss
Increase (Decrease) Accumulated Other Comprehensive Loss, Net of Tax
Balance at beginning of the period	(2,017)	(1,494)
Change before reclassifications	90	(253)
Amounts reclassified from accumulated other comprehensive income	(45)	21
Translation effect	1	15
Tax effect		1
Other comprehensive income (loss) attributable to the Company	46	(216)
Balance at end of the period	$ (1,971)	$ (1,710)