Consolidated Statements of Cash Flows - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Cash flows from operating activities:
Net income	$ 68	$ 67
Adjustments to reconcile net income to net cash flows from operating activities:
Loss on nonrecurring items	0	14
Depreciation and amortization	84	79
Allowance for equity funds	(2)	(3)
Deferred income taxes and amortization of investment tax credits	38	37
Amortization of deferred energy	20	7
Deferred energy	68	(34)
Amortization of other regulatory assets and liabilities	(9)	36
Other, net	0	(19)
Changes in other operating assets and liabilities:
Accounts receivable and other assets	10	24
Accounts payable and other liabilities	14	(27)
Net cash flows from operating activities	291	181
Cash flows from investing activities:
Capital expenditures	(153)	(117)
Payments for (Proceeds from) Other Investing Activities	2	0
Net cash flows from investing activities	(151)	(117)
Cash flows from financing activities: [Abstract]
Repayments of long-term debt and capital lease obligations	1	0
Dividends paid	(7)	0
Net Cash Provided by (Used in) Financing Activities	(8)	0
Net change in cash and cash equivalents	132	64
Cash and cash equivalents at beginning of period	22	67
Cash and cash equivalents at end of period	$ 154	$ 131