Income Taxes Schedule of Deferred tax Assets and Liabilities (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Deferred income tax assets:
Price risk management	$ 71	$ 77
Employee benefits	122	162
Deferred Tax Assets, tax credits, net of valuation allowance	51	55
Deferred income taxes	16	20
Deferred Tax Assets, Tax Deferred Expense, Other	17	0
Total deferred income tax assets	277	314
Deferred income tax liabilities:
Depreciation and amortization	646	623
Regulatory assets	175	224
Other	0	4
Total deferred income tax liabilities	821	851
Deferred income tax liability, net	(544)	(537)
Classification of net deferred income taxes:
Current deferred income tax asset	42	51
Noncurrent deferred income tax liability	$ (586)	$ (588)