Fair Value Measurements (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2014 Carrying Amount [Member]		Dec. 31, 2013 Carrying Amount [Member]		Mar. 31, 2014 Carrying Amount [Member] Former Venezuela Operations [Member]	Mar. 31, 2014 Fair Value [Member]		Dec. 31, 2013 Fair Value [Member]		Mar. 31, 2014 Fair Value [Member] Former Venezuela Operations [Member]	Mar. 31, 2014 Level 1 [Member]		Dec. 31, 2013 Level 1 [Member]		Mar. 31, 2014 Level 2 [Member]		Dec. 31, 2013 Level 2 [Member]		Mar. 31, 2014 Level 3 [Member]		Dec. 31, 2013 Level 3 [Member]		Mar. 31, 2014 Fair Value, Measurements, Recurring [Member] Carrying Amount [Member]	Dec. 31, 2013 Fair Value, Measurements, Recurring [Member] Carrying Amount [Member]	Mar. 31, 2014 Fair Value, Measurements, Recurring [Member] Carrying Amount [Member] Not Designated as Hedging Instrument [Member]	Dec. 31, 2013 Fair Value, Measurements, Recurring [Member] Carrying Amount [Member] Not Designated as Hedging Instrument [Member]	Mar. 31, 2014 Fair Value, Measurements, Recurring [Member] Fair Value [Member]	Dec. 31, 2013 Fair Value, Measurements, Recurring [Member] Fair Value [Member]	Mar. 31, 2014 Fair Value, Measurements, Recurring [Member] Fair Value [Member] Not Designated as Hedging Instrument [Member]	Dec. 31, 2013 Fair Value, Measurements, Recurring [Member] Fair Value [Member] Not Designated as Hedging Instrument [Member]	Mar. 31, 2014 Fair Value, Measurements, Recurring [Member] Level 1 [Member]	Dec. 31, 2013 Fair Value, Measurements, Recurring [Member] Level 1 [Member]	Mar. 31, 2014 Fair Value, Measurements, Recurring [Member] Level 1 [Member] Not Designated as Hedging Instrument [Member]	Dec. 31, 2013 Fair Value, Measurements, Recurring [Member] Level 1 [Member] Not Designated as Hedging Instrument [Member]	Mar. 31, 2014 Fair Value, Measurements, Recurring [Member] Level 2 [Member]	Dec. 31, 2013 Fair Value, Measurements, Recurring [Member] Level 2 [Member]	Mar. 31, 2014 Fair Value, Measurements, Recurring [Member] Level 2 [Member] Not Designated as Hedging Instrument [Member]	Dec. 31, 2013 Fair Value, Measurements, Recurring [Member] Level 2 [Member] Not Designated as Hedging Instrument [Member]	Mar. 31, 2014 Fair Value, Measurements, Recurring [Member] Level 3 [Member]	Dec. 31, 2013 Fair Value, Measurements, Recurring [Member] Level 3 [Member]	Mar. 31, 2014 Fair Value, Measurements, Recurring [Member] Level 3 [Member] Not Designated as Hedging Instrument [Member]	Dec. 31, 2013 Fair Value, Measurements, Recurring [Member] Level 3 [Member] Not Designated as Hedging Instrument [Member]
Measured on a recurring basis:
ARO Trust investments																									$ 45	$ 33			$ 45	$ 33			$ 45	$ 33			$ 0	$ 0			$ 0	$ 0
Energy derivatives assets																											3	3			3	3			0	0			0	0			3	3
Energy derivative liabilities																											(2)	(3)			(2)	(3)			0	0			0	(1)			(2)	(2)
Additional disclosure:
Notes receivable and other			75		77			130		140			2		1		6		6		122		133
Long-term debt, including current portion			(12,849)	[1]	(11,353)	[1]		(13,790)	[1]	(11,971)	[1]		0	[1]	0	[1]	(13,790)	[1]	(11,971)	[1]	0	[1]	0	[1]
Guarantee			(31)		(32)			(28)		(29)			0		0		(28)		(29)		0		0
Fair Value, Level 1 to level 2 Transfers, Amount	0	0
Fair Value, Level 2 to level 1 Transfers, Amount	0	0
Notes Receivable, Fair Value Disclosure							$ 32					$ 87

[1] Excludes capital leases