Derivative Instruments and Hedging Activities - Part 1 (Details) In Millions, unless otherwise specified	3 Months Ended													3 Months Ended					3 Months Ended
	Mar. 31, 2013 Interest Rate Derivatives Libor USD [Member]	Mar. 31, 2013 Interest Rate Derivatives Euribor EUR [Member]	Mar. 31, 2013 Interest Rate Derivatives Libor GBP [Member]	Mar. 31, 2013 Interest Rate Derivatives Current Notional [Member] Libor USD [Member] USD ($)	Mar. 31, 2013 Interest Rate Derivatives Current Notional [Member] Euribor EUR [Member] USD ($)	Mar. 31, 2013 Interest Rate Derivatives Current Notional [Member] Euribor EUR [Member] EUR (€)	Mar. 31, 2013 Interest Rate Derivatives Current Notional [Member] Libor GBP [Member] USD ($)	Mar. 31, 2013 Interest Rate Derivatives Current Notional [Member] Libor GBP [Member] GBP (£)	Mar. 31, 2013 Interest Rate Derivatives Maximum Libor USD [Member] USD ($)	Mar. 31, 2013 Interest Rate Derivatives Maximum Euribor EUR [Member] USD ($)	Mar. 31, 2013 Interest Rate Derivatives Maximum Euribor EUR [Member] EUR (€)	Mar. 31, 2013 Interest Rate Derivatives Maximum Libor GBP [Member] USD ($)	Mar. 31, 2013 Interest Rate Derivatives Maximum Libor GBP [Member] GBP (£)	Mar. 31, 2013 Cross Currency Swaps Chilean Unidad De Fomento CLF [Member]	Mar. 31, 2013 Cross Currency Swaps Current Notional [Member] Chilean Unidad De Fomento CLF [Member] USD ($)	Mar. 31, 2013 Cross Currency Swaps Current Notional [Member] Chilean Unidad De Fomento CLF [Member] CLF	Mar. 31, 2013 Cross Currency Swaps Maximum Chilean Unidad De Fomento CLF [Member] USD ($)	Mar. 31, 2013 Cross Currency Swaps Maximum Chilean Unidad De Fomento CLF [Member] CLF	Mar. 31, 2013 Foreign Currency Options Euro EUR [Member] USD ($)	Mar. 31, 2013 Foreign Currency Options Euro EUR [Member] EUR (€)	Mar. 31, 2013 Foreign Currency Options Brazilian Real BRL [Member] USD ($)	Mar. 31, 2013 Foreign Currency Options Brazilian Real BRL [Member] BRL	Mar. 31, 2013 Foreign Currency Options British Pound GBP [Member] USD ($)	Mar. 31, 2013 Foreign Currency Options British Pound GBP [Member] GBP (£)	Mar. 31, 2013 Foreign Currency Options Chilean Peso CLP [Member] USD ($)	Mar. 31, 2013 Foreign Currency Options Chilean Peso CLP [Member] CLP	Mar. 31, 2013 Foreign Currency Options Colombian Peso COP [Member] USD ($)	Mar. 31, 2013 Foreign Currency Options Colombian Peso COP [Member] COP	Mar. 31, 2013 Foreign Currency Options Argentine Peso ARS [Member] USD ($)	Mar. 31, 2013 Foreign Currency Options Argentine Peso ARS [Member] ARS	Mar. 31, 2013 Embedded Foreign Currency Derivatives Euro EUR [Member] USD ($)	Mar. 31, 2013 Embedded Foreign Currency Derivatives Euro EUR [Member] EUR (€)	Mar. 31, 2013 Embedded Foreign Currency Derivatives Argentine Peso ARS [Member] USD ($)	Mar. 31, 2013 Embedded Foreign Currency Derivatives Argentine Peso ARS [Member] ARS	Mar. 31, 2013 Embedded Foreign Currency Derivatives Kazakhstani Tenge KZT [Member] USD ($)	Mar. 31, 2013 Embedded Foreign Currency Derivatives Kazakhstani Tenge KZT [Member] KZT	Mar. 31, 2013 Commodity Derivatives Aluminum M Wh [Member] MWh	Mar. 31, 2013 Commodity Derivatives Power MWh [Member] MWh
Derivative Tables [Line Items]
Notional Amount Of Interest Rate Derivatives				$ 3,451	$ 776	€ 605	$ 105	£ 69	$ 4,226	$ 776	€ 605	$ 105	£ 69
Weighted Average Remaining Term	9 years	9 years	13 years											9 years																	10 years	10 years	11 years	11 years	5 years	5 years	7 years	3 years
Weighted Average Remaining Term (string type)																			<1	<1	<1	<1	<1	<1	<1	<1	<1	<1	<1	<1
% of Debt Currently Hedged by Index	70.00%	67.00%	83.00%											85.00%
Notional Amount Of Foreign Currency Derivatives															271		271		41	29	118	240	5	3	166	80,558	28	53,208	14	83	2	2	169	829	7	1,009
Notional (CLF)																6		6
Notional (MWh)																																					14,000,000	6,000,000