Regulatory Matters (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2013		Dec. 31, 2012
Schedule Of Regulatory Assets And Liabilities [Line Items]
Regulatory liabilities	$ (642)		$ (619)
Net Regulatory Assets (Liabilities)	(542)		(514)
Other Longterm Regulatory Assets Member
Schedule Of Regulatory Assets And Liabilities [Line Items]
Regulatory assets in other long-term assets (1)	$ 100	[1]	$ 105	[1]

[1] Regulatory assets that are not earning a return were not material at December 31, 2013 or 2012.