Reclassifications out of Accumulated Other Comprehensive Loss Changes in Accumulated Other Comprehensive Loss by Component (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Balance at beginning of period	$ (4,131)	$ (3,935)
Other comprehensive income (loss) before reclassifications	(308)	(303)
Amounts reclassified from accumulated other comprehensive loss	288	108
Purchase of subsidiary shares from minority interest	(107)	(1)
Deconsolidation of Venezuelan subsidiary	248
Balance at end of period	(4,010)	(4,131)
Foreign Currency Translation Adjustment
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Balance at beginning of period	(894)	(690)
Other comprehensive income (loss) before reclassifications	(251)	(206)
Amounts reclassified from accumulated other comprehensive loss	16	3
Purchase of subsidiary shares from minority interest	(3)	(1)
Deconsolidation of Venezuelan subsidiary	186
Balance at end of period	(946)	(894)
Unrecognized Net Actuarial Losses and Prior Service Costs
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Balance at beginning of period	(3,285)	(3,278)
Other comprehensive income (loss) before reclassifications	(68)	(112)
Amounts reclassified from accumulated other comprehensive loss	325	105
Purchase of subsidiary shares from minority interest	(105)	0
Deconsolidation of Venezuelan subsidiary	62
Balance at end of period	(3,071)	(3,285)
Deferred Derivative Gains (Losses)
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Balance at beginning of period	12	(1)
Other comprehensive income (loss) before reclassifications	15	13
Amounts reclassified from accumulated other comprehensive loss	(21)	0
Purchase of subsidiary shares from minority interest	1	0
Deconsolidation of Venezuelan subsidiary	0
Balance at end of period	7	12
Unrealized Investment Gains
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Balance at beginning of period	36	34
Other comprehensive income (loss) before reclassifications	(4)	2
Amounts reclassified from accumulated other comprehensive loss	(32)	0
Purchase of subsidiary shares from minority interest		0
Deconsolidation of Venezuelan subsidiary	0
Balance at end of period	$ 0	$ 36