Derivative Instruments and Hedging Activities - Part 1 (Details) - USD ($)	3 Months Ended			6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Mar. 31, 2018	Jun. 30, 2019	Dec. 31, 2018
Foreign Exchange Contract [Member]
Derivative Tables [Line Items]
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Gain (Loss) Included in Earnings	$ 1,000,000	$ (3,000,000)	$ 3,000,000	$ 5,000,000
Fair Value Measurements With Unobservable Inputs Reconciliation Recurring Basis Regulatory Assets Liabilities	0	0	0	0
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Settlements	1,000,000	9,000,000	18,000,000	2,000,000
Derivative Liability, Fair Value, Gross Liability	(29,000,000)			(29,000,000)	$ (41,000,000)
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Period Increase (Decrease)	(2,000,000)	(5,000,000)	(21,000,000)	(6,000,000)
Interest Rate Contract [Member]
Derivative Tables [Line Items]
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Gain (Loss) Included in Earnings	1,000,000	(13,000,000)	(27,000,000)	1,000,000
Fair Value Measurements With Unobservable Inputs Reconciliation Recurring Basis Regulatory Assets Liabilities	0	0	0	0
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Settlements	(2,000,000)	(4,000,000)	(10,000,000)	(4,000,000)
Derivative Liability, Fair Value, Gross Liability	(402,000,000)			(402,000,000)	(208,000,000)
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Period Increase (Decrease)	0	15,000,000	31,000,000	0
Interest Rate Contract [Member] | Libor and Euribor [Member]
Derivative Tables [Line Items]
Derivatives, notional amount	6,174,000,000			6,174,000,000
Cross currency derivatives [Member]
Derivative Tables [Line Items]
Derivative Liability, Fair Value, Gross Liability	(3,000,000)			(3,000,000)	(5,000,000)
Commodity Contract [Member]
Derivative Tables [Line Items]
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Gain (Loss) Included in Earnings	(1,000,000)	0	(1,000,000)	(1,000,000)
Fair Value Measurements With Unobservable Inputs Reconciliation Recurring Basis Regulatory Assets Liabilities	1,000,000	9,000,000	9,000,000	(1,000,000)
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Settlements	0	2,000,000	4,000,000	0
Derivative Liability, Fair Value, Gross Liability	(24,000,000)			(24,000,000)	(3,000,000)
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Period Increase (Decrease)	1,000,000	0	1,000,000	0
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Gain (Loss) Included in Earnings	1,000,000	(16,000,000)	(25,000,000)	5,000,000
Fair Value Measurements With Unobservable Inputs Reconciliation Recurring Basis Regulatory Assets Liabilities	1,000,000	9,000,000	9,000,000	(1,000,000)
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Settlements	(1,000,000)	7,000,000	12,000,000	(2,000,000)
Derivative Liability, Fair Value, Gross Liability	(458,000,000)			(458,000,000)	$ (257,000,000)
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Period Increase (Decrease)	(1,000,000)	10,000,000	11,000,000	(6,000,000)
Natural Gas and Natural Gas Liquids [Member]
Derivative Tables [Line Items]
Commodity Contract Asset, Current	57,000,000			57,000,000
Energy [Domain]
Derivative Tables [Line Items]
Commodity Contract Asset, Current	10,000,000			10,000,000
Coal [Member]
Derivative Tables [Line Items]
Commodity Contract Asset, Current	10,000,000			10,000,000
Fuel [Member]
Derivative Tables [Line Items]
Commodity Contract Asset, Current	1,000,000			1,000,000
Unidad de Fomento (funds code) | Cross currency derivatives [Member]
Derivative Tables [Line Items]
Derivatives, notional amount	304,000,000			304,000,000
Euro EUR [Member] | Foreign Exchange Contract [Member]
Derivative Tables [Line Items]
Derivatives, notional amount	17,000,000			17,000,000
Argentina, Pesos | Foreign Exchange Contract [Member]
Derivative Tables [Line Items]
Derivatives, notional amount	49,000,000			49,000,000
Chile, Pesos | Foreign Exchange Contract [Member]
Derivative Tables [Line Items]
Derivatives, notional amount	223,000,000			223,000,000
Colombia, Pesos | Foreign Exchange Contract [Member]
Derivative Tables [Line Items]
Derivatives, notional amount	223,000,000			223,000,000
Other unspecified currency [Domain] | Foreign Exchange Contract [Member]
Derivative Tables [Line Items]
Derivatives, notional amount	216,000,000			216,000,000
Other comprehensive income - Derivative activity [Member] | Foreign Exchange Contract [Member]
Derivative Tables [Line Items]
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Gain (Loss) Included in Other Comprehensive Income (Loss)	0	0	0	0
Other comprehensive income - Derivative activity [Member] | Interest Rate Contract [Member]
Derivative Tables [Line Items]
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Gain (Loss) Included in Other Comprehensive Income (Loss)	(75,000,000)	1,000,000	32,000,000	(88,000,000)
Other comprehensive income - Derivative activity [Member] | Commodity Contract [Member]
Derivative Tables [Line Items]
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Gain (Loss) Included in Other Comprehensive Income (Loss)	0	0	0	0
Other comprehensive income - Derivative activity [Member]
Derivative Tables [Line Items]
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Gain (Loss) Included in Other Comprehensive Income (Loss)	$ (75,000,000)	$ 1,000,000	$ 32,000,000	$ (88,000,000)