STATEMENTS OF CONSOLIDATED CASH FLOWS - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Cash Flows from Operating Activities:
Net income	$ 433	$ 276	$ 261
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	724	838	705
Amortization of deferred financing costs	13	14	15
Deferred income taxes	(98)	(34)	18
Changes in other assets and liabilities:
Accounts and notes receivable, net	(73)	(1)	3
Accounts receivable/payable–affiliated companies	(46)	63	(89)
Inventory	15	(1)	(7)
Accounts payable	59	(4)	0
Taxes receivable	6	53	44
Interest and taxes accrued	7	4	(9)
Net regulatory assets and liabilities	(148)	(110)	3
Other current assets	(2)	2	(1)
Other current liabilities	16	21	(40)
Other assets	13	(8)	(7)
Other liabilities	(4)	(4)	(1)
Other, net	(6)	1	0
Net cash provided by operating activities	909	1,110	895
Cash Flows from Investing Activities:
Capital expenditures	(875)	(862)	(929)
Decrease (increase) in notes receivable–affiliated companies	96	(96)	107
Decrease (increase) in restricted cash of Bond Companies	5	(5)	12
Other, net	(2)	(1)	1
Net cash used in investing activities	(776)	(964)	(809)
Cash Flows from Financing Activities:
Proceeds from long-term debt, net	298	600	200
Payments of long-term debt	(411)	(590)	(372)
Dividend to parent	(180)	(135)	(252)
Increase (decrease) in notes payable–affiliated companies	60	(312)	312
Debt issuance costs	(3)	(6)	0
Contribution from parent	0	374	0
Net cash used in financing activities	(236)	(69)	(112)
Net Increase (Decrease) in Cash and Cash Equivalents	(103)	77	(26)
Cash and Cash Equivalents at Beginning of the Year	341	264	290
Cash and Cash Equivalents at End of the Year	238	341	264
Cash Payments:
Interest, net of capitalized interest	205	209	213
Income taxes	76	128	81
Non-cash transactions:
Accounts payable related to capital expenditures	$ 104	$ 65	$ 69