Derivative Instruments and Hedging Activities - Part 3 (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Gain Loss By Type Of Derivative Tables
Gain (Losses) Recognized in AOCL	$ (127)	$ 130	$ (271)	$ 114
Gains (Losses) Reclassified from AOCL into Earnings	(23)	(76)	(45)	(107)
Gains (Losses) Recognized in Earnings (ineffective portion)	0	31	0	30
Gains (Losses) Recognized in Earnings (not designated as hedging instruments)	90	33	99	8
AOCI to be recognized in next 12 months table
Gain on Discontinuation of Cash Flow Hedge Due to Forecasted Transaction Probable of Not Occurring	6	0
Interest rate derivatives [Member]
Gain Loss By Type Of Derivative Tables
Gain (Losses) Recognized in AOCL	(124)	134	(274)	121
AOCI to be recognized in next 12 months table
Accumulated Other Comprehensive Income Loss Before Tax Expected Increase Decrease Next Twelve Months	(117)		(117)
Interest rate derivatives [Member] | Interest Expense [Member]
Gain Loss By Type Of Derivative Tables
Gains (Losses) Reclassified from AOCL into Earnings	(33)	(31)	(64)	(63)
Gains (Losses) Recognized in Earnings (ineffective portion)	1	31	1	30
Gains (Losses) Recognized in Earnings (not designated as hedging instruments)	0	1	0	2
Interest rate derivatives [Member] | Non-regulated cost of sales [Member]
Gain Loss By Type Of Derivative Tables
Gains (Losses) Reclassified from AOCL into Earnings	0	(1)	(1)	(2)
Interest rate derivatives [Member] | Net Equity In Earnings Of Affiliates [Member]
Gain Loss By Type Of Derivative Tables
Gains (Losses) Reclassified from AOCL into Earnings	(2)	(2)	(3)	(4)
Gains (Losses) Recognized in Earnings (not designated as hedging instruments)	0	0	0	(6)
Cash Flow Hedging [Member] | Interest rate derivatives [Member] | Sale of Subsidiary Gain (Loss) [Member]
Gain Loss By Type Of Derivative Tables
Gains (Losses) Reclassified from AOCL into Earnings	0	(21)	0	(21)
Cross currency derivatives [Member]
Gain Loss By Type Of Derivative Tables
Gain (Losses) Recognized in AOCL	0	(12)	(3)	(11)
AOCI to be recognized in next 12 months table
Accumulated Other Comprehensive Income Loss Before Tax Expected Increase Decrease Next Twelve Months	(4)		(4)
Cross currency derivatives [Member] | Interest Expense [Member]
Gain Loss By Type Of Derivative Tables
Gains (Losses) Reclassified from AOCL into Earnings	2	(3)	1	(6)
Gains (Losses) Recognized in Earnings (ineffective portion)	(1)	0	(1)	0
Cross currency derivatives [Member] | Foreign currency transaction gains (losses) [Member]
Gain Loss By Type Of Derivative Tables
Gains (Losses) Reclassified from AOCL into Earnings	4	(19)	(6)	(14)
Foreign currency derivatives [Member]
Gain Loss By Type Of Derivative Tables
Gain (Losses) Recognized in AOCL	3	1	(12)	2
AOCI to be recognized in next 12 months table
Accumulated Other Comprehensive Income Loss Before Tax Expected Increase Decrease Next Twelve Months	(5)		(5)
Foreign currency derivatives [Member] | Net Equity In Earnings Of Affiliates [Member]
Gain Loss By Type Of Derivative Tables
Gains (Losses) Recognized in Earnings (not designated as hedging instruments)	9	(12)	5	(15)
Foreign currency derivatives [Member] | Foreign currency transaction gains (losses) [Member]
Gain Loss By Type Of Derivative Tables
Gains (Losses) Reclassified from AOCL into Earnings	3	2	10	4
Gains (Losses) Recognized in Earnings (not designated as hedging instruments)	6	17	29	23
Commodity derivatives [Member]
Gain Loss By Type Of Derivative Tables
Gain (Losses) Recognized in AOCL	(6)	7	18	2
AOCI to be recognized in next 12 months table
Accumulated Other Comprehensive Income Loss Before Tax Expected Increase Decrease Next Twelve Months	(6)		(6)
Commodity derivatives [Member] | Non-regulated cost of sales [Member]
Gain Loss By Type Of Derivative Tables
Gains (Losses) Reclassified from AOCL into Earnings	(3)	0	(1)	0
Gains (Losses) Recognized in Earnings (not designated as hedging instruments)	2	0	2	1
Commodity derivatives [Member] | Non-regulated revenue [Member]
Gain Loss By Type Of Derivative Tables
Gains (Losses) Reclassified from AOCL into Earnings	6	(1)	19	(1)
Gains (Losses) Recognized in Earnings (not designated as hedging instruments)	1	12	4	4
Commodity derivatives [Member] | Regulated Revenue [Member]
Gain Loss By Type Of Derivative Tables
Gains (Losses) Recognized in Earnings (not designated as hedging instruments)	0	3	0	0
Commodity derivatives [Member] | Regulated Cost Of Sales [Member]
Gain Loss By Type Of Derivative Tables
Gains (Losses) Recognized in Earnings (not designated as hedging instruments)	2	11	(6)	11
Commodity derivatives [Member] | Income (Loss) From Operations Of Discontinued Business [Member]
Gain Loss By Type Of Derivative Tables
Gains (Losses) Recognized in Earnings (not designated as hedging instruments)	(2)	1	(7)	(12)
Commodity derivatives [Member] | Net Loss from Disposal and Impairments of Discontinued Business [Member]
Gain Loss By Type Of Derivative Tables
Gains (Losses) Recognized in Earnings (not designated as hedging instruments)	$ 72	$ 0	$ 72	$ 0