Consolidated Statements of Cash Flows - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014
Cash flows from operating activities:
Net income	$ 35	$ 36
Adjustments to reconcile net income to net cash flows from operating activities:
Depreciation and amortization	56	52
Allowance for equity funds	(1)	(2)
Deferred income taxes and amortization of investment tax credits	19	19
Amortization of Deferred Charges	19	2
Deferred Energy Change	47	(31)
Amortization of other regulatory assets	(6)	28
Other, net	(3)	(9)
Changes in other operating assets and liabilities:
Accounts receivable and other assets	7	22
Inventories	(2)	(4)
Accounts payable and other liabilities	25	(9)
Net cash flows from operating activities	196	104
Cash flows from investing activities:
Capital expenditures	(98)	(88)
Payments for (Proceeds from) Other Investing Activities	2	0
Net cash flows from investing activities	(96)	(88)
Cash flows from financing activities: [Abstract]
Payments of Ordinary Dividends, Common Stock	(7)	0
Net Cash Provided by (Used in) Financing Activities	(7)	0
Net change in cash and cash equivalents	93	16
Cash and cash equivalents at beginning of period	22	67
Cash and cash equivalents at end of period	$ 115	$ 83