Derivative Instruments and Hedging Activities - Part 1 (Details) - Jun. 30, 2015 € in Millions, £ in Millions, T in Millions, PHP in Millions, MWh in Millions, KZT in Millions, COP in Millions, CLP in Millions, CLF in Millions, BRL in Millions, ARS in Millions, $ in Millions		USD ($) MWh T	PHP MWh T		CLF MWh T		BRL MWh T		COP MWh T		KZT MWh T		EUR (€) MWh T		CLP MWh T		ARS MWh T		GBP (£) MWh T
Interest Rate Contract [Member] | Libor USD [Member]
Derivative Tables [Line Items]
Weighted Average Remaining Term (less than 1 for Foreign Currency Derivatives for Chilean Peso, Chilean Unidad de Fomento, Brazilian Real, Euro, Colombian Peso, British Pound, and Philippine Peso)	[1]	11 years
% of Debt Currently Hedged by Index	[1],[2]	55.00%	55.00%		55.00%		55.00%		55.00%		55.00%		55.00%		55.00%		55.00%		55.00%
Interest Rate Contract [Member] | Euribor EUR [Member]
Derivative Tables [Line Items]
Weighted Average Remaining Term (less than 1 for Foreign Currency Derivatives for Chilean Peso, Chilean Unidad de Fomento, Brazilian Real, Euro, Colombian Peso, British Pound, and Philippine Peso)	[1]	7 years
% of Debt Currently Hedged by Index	[1],[2]	75.00%	75.00%		75.00%		75.00%		75.00%		75.00%		75.00%		75.00%		75.00%		75.00%
Interest Rate Contract [Member] | Maximum [Member] | Libor USD [Member]
Derivative Tables [Line Items]
Derivatives, notional amount	[1]	$ 3,061
Interest Rate Contract [Member] | Maximum [Member] | Euribor EUR [Member]
Derivative Tables [Line Items]
Derivatives, notional amount	[1]	564											€ 506
Interest Rate Contract [Member] | Current Notional [Member] | Libor USD [Member]
Derivative Tables [Line Items]
Derivatives, notional amount	[1]	2,689
Interest Rate Contract [Member] | Current Notional [Member] | Euribor EUR [Member]
Derivative Tables [Line Items]
Derivatives, notional amount	[1]	$ 564											€ 506
Cross currency derivatives [Member] | Chilean Unidad De Fomento CLF [Member]
Derivative Tables [Line Items]
Weighted Average Remaining Term (less than 1 for Foreign Currency Derivatives for Chilean Peso, Chilean Unidad de Fomento, Brazilian Real, Euro, Colombian Peso, British Pound, and Philippine Peso)	[1]	13 years
% of Debt Currently Hedged by Index	[1],[2]	82.00%	82.00%		82.00%		82.00%		82.00%		82.00%		82.00%		82.00%		82.00%		82.00%
Cross currency derivatives [Member] | Maximum [Member] | Chilean Unidad De Fomento CLF [Member]
Derivative Tables [Line Items]
Derivatives, notional amount	[1]	$ 172			CLF 4
Cross currency derivatives [Member] | Current Notional [Member] | Chilean Unidad De Fomento CLF [Member]
Derivative Tables [Line Items]
Derivatives, notional amount	[1]	172			4
Foreign Currency Options [ Member] | Chilean Unidad De Fomento CLF [Member]
Derivative Tables [Line Items]
Derivatives, notional amount		$ 311			CLF 8	[3]
Weighted Average Remaining Term (less than 1 for Foreign Currency Derivatives for Chilean Peso, Chilean Unidad de Fomento, Brazilian Real, Euro, Colombian Peso, British Pound, and Philippine Peso)		1 year
Weighted Average Remaining Term (string type)	[4]	<1
Foreign Currency Options [ Member] | Chilean Peso CLP [Member]
Derivative Tables [Line Items]
Derivatives, notional amount		$ 126													CLP 80,373	[3]
Weighted Average Remaining Term (less than 1 for Foreign Currency Derivatives for Chilean Peso, Chilean Unidad de Fomento, Brazilian Real, Euro, Colombian Peso, British Pound, and Philippine Peso)		1 year
Weighted Average Remaining Term (string type)	[4]	<1
Foreign Currency Options [ Member] | Brazilian Real BRL [Member]
Derivative Tables [Line Items]
Derivatives, notional amount		$ 33					BRL 103	[3]
Weighted Average Remaining Term (less than 1 for Foreign Currency Derivatives for Chilean Peso, Chilean Unidad de Fomento, Brazilian Real, Euro, Colombian Peso, British Pound, and Philippine Peso)		1 year
Weighted Average Remaining Term (string type)	[4]	<1
Foreign Currency Options [ Member] | Euro EUR [Member]
Derivative Tables [Line Items]
Derivatives, notional amount		$ 119											€ 107	[3]
Weighted Average Remaining Term (less than 1 for Foreign Currency Derivatives for Chilean Peso, Chilean Unidad de Fomento, Brazilian Real, Euro, Colombian Peso, British Pound, and Philippine Peso)		1 year
Weighted Average Remaining Term (string type)	[4]	<1
Foreign Currency Options [ Member] | Colombian Peso COP [Member]
Derivative Tables [Line Items]
Derivatives, notional amount		$ 56							COP 145,874	[3]
Weighted Average Remaining Term (less than 1 for Foreign Currency Derivatives for Chilean Peso, Chilean Unidad de Fomento, Brazilian Real, Euro, Colombian Peso, British Pound, and Philippine Peso)		1 year
Weighted Average Remaining Term (string type)	[4]	<1
Foreign Currency Options [ Member] | Argentine Peso ARS [Member]
Derivative Tables [Line Items]
Derivatives, notional amount		$ 224															ARS 2,032	[3]
Weighted Average Remaining Term (less than 1 for Foreign Currency Derivatives for Chilean Peso, Chilean Unidad de Fomento, Brazilian Real, Euro, Colombian Peso, British Pound, and Philippine Peso)		10 years
Weighted Average Remaining Term (string type)	[4]	10
Foreign Currency Options [ Member] | British Pound GBP [Member]
Derivative Tables [Line Items]
Derivatives, notional amount		$ 24																	£ 16	[3]
Weighted Average Remaining Term (less than 1 for Foreign Currency Derivatives for Chilean Peso, Chilean Unidad de Fomento, Brazilian Real, Euro, Colombian Peso, British Pound, and Philippine Peso)		1 year
Weighted Average Remaining Term (string type)	[4]	<1
Foreign Currency Options [ Member] | Philippine Peso PHP [Member]
Derivative Tables [Line Items]
Derivatives, notional amount		$ 17	PHP 751	[3]
Weighted Average Remaining Term (less than 1 for Foreign Currency Derivatives for Chilean Peso, Chilean Unidad de Fomento, Brazilian Real, Euro, Colombian Peso, British Pound, and Philippine Peso)		1 year
Weighted Average Remaining Term (string type)	[4]	<1
Embedded Foreign Currency Derivatives [Member] | Kazakhstani Tenge KZT [Member]
Derivative Tables [Line Items]
Derivatives, notional amount		$ 20									KZT 3,761	[3]
Weighted Average Remaining Term (less than 1 for Foreign Currency Derivatives for Chilean Peso, Chilean Unidad de Fomento, Brazilian Real, Euro, Colombian Peso, British Pound, and Philippine Peso)	[4]	1 year
Commodity Contract [Member] | Power MWh [Member]
Derivative Tables [Line Items]
Weighted Average Remaining Term (less than 1 for Foreign Currency Derivatives for Chilean Peso, Chilean Unidad de Fomento, Brazilian Real, Euro, Colombian Peso, British Pound, and Philippine Peso)	[5]	2 years
Notional (MWh) | MWh		9	9		9		9		9		9		9		9		9		9
Commodity Contract [Member] | Coal Metric Tons [Member]
Derivative Tables [Line Items]
Weighted Average Remaining Term (less than 1 for Foreign Currency Derivatives for Chilean Peso, Chilean Unidad de Fomento, Brazilian Real, Euro, Colombian Peso, British Pound, and Philippine Peso)	[5]	2 years
Notional (MWh) | T		1	1		1		1		1		1		1		1		1		1

[1] The Company’s interest rate derivative instruments primarily include accreting and amortizing notionals. The maximum derivative notional represents the largest notional at any point between June 30, 2015 and the maturity of the derivative instrument, which includes forward-starting derivative instruments. The interest rate and cross-currency derivatives range in maturity through 2033 and 2028, respectively.

[2] The percentage of variable-rate debt currently hedged is based on the related index and excludes forecasted issuances of debt and variable-rate debt tied to other indices where the Company has no interest rate derivatives.

[3] Represents contractual notionals. The notionals for options have not been probability adjusted, which generally would decrease them.

[4] Represents the remaining tenor of our foreign currency derivatives weighted by the corresponding notional. These options and forwards and these embedded derivatives range in maturity through 2025 and 2017, respectively.

[5] Represents the remaining tenor of our commodity derivatives weighted by the corresponding volume. These derivatives range in maturity through 2017.