Equity (Accumulated Other Comprehensive Loss) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Net of Tax, Beginning Balance	$ (2,147,000,000)	$ (3,256,000,000)
Accumulated Other Comprehensive Income (Loss), Cumulative Changes in Net Gain (Loss) from Cash Flow Hedges, Effect Net of Tax, Beginning Balance	(323,000,000)	(353,000,000)
Accumulated Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net of Tax, Beginning Balance	(286,000,000)	(274,000,000)
Accumulated Other Comprehensive Income (Loss), Net of Tax, Beginning Balance	(2,756,000,000)	(3,883,000,000)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	(15,000,000)	106,000,000
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	928,000,000	1,021,000,000
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax	634,000,000	1,181,000,000	$ (1,019,000,000)
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax	38,000,000	42,000,000	9,000,000
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax	247,000,000	(187,000,000)	77,000,000
Other Comprehensive Income (Loss), Net of Tax	919,000,000	1,036,000,000	(933,000,000)
Accumulated Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Net of Tax, Ending Balance	(1,486,000,000)	(2,147,000,000)	(3,256,000,000)
Accumulated Other Comprehensive Income (Loss), Cumulative Changes in Net Gain (Loss) from Cash Flow Hedges, Effect Net of Tax, Ending Balance	(333,000,000)	(323,000,000)	(353,000,000)
Accumulated Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net of Tax, Ending Balance	(57,000,000)	(286,000,000)	(274,000,000)
Accumulated Other Comprehensive Income (Loss), Net of Tax, Ending Balance	(1,876,000,000)	(2,756,000,000)	(3,883,000,000)
Available-for-Sale securities, net
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	18,000,000	117,000,000
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	643,000,000	992,000,000
Unrealized derivative gains (losses), net
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	(14,000,000)	2,000,000
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	37,000,000	28,000,000
Unfunded pension obligations, net
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	(19,000,000)	(13,000,000)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	248,000,000	1,000,000
Accumulated Other Comprehensive Loss
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax	661,000,000	1,109,000,000	(674,000,000)
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax	23,000,000	30,000,000	43,000,000
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax	229,000,000	(12,000,000)	21,000,000
Other Comprehensive Income (Loss), Net of Tax	913,000,000	$ 1,127,000,000	(610,000,000)
Cumulative Effect of New Accounting Principle in Period of Adoption	0		$ 13,000,000
Alto Maipo [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Net of Tax, Ending Balance	0
Accumulated Other Comprehensive Income (Loss), Cumulative Changes in Net Gain (Loss) from Cash Flow Hedges, Effect Net of Tax, Ending Balance	(33,000,000)
Accumulated Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net of Tax, Ending Balance	0
Accumulated Other Comprehensive Income (Loss), Net of Tax, Ending Balance	$ (33,000,000)