CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
OPERATING REVENUES
Total operating revenues	$ 2,101	$ 2,133	$ 4,231	$ 4,295
OPERATING EXPENSES
Cost of services and products (exclusive of depreciation and amortization)	702	723	1,409	1,443
Selling, general and administrative	215	235	430	479
Operating expenses - affiliates	197	209	413	436
Depreciation and amortization	361	393	721	784
Total operating expenses	1,475	1,560	2,973	3,142
OPERATING INCOME	626	573	1,258	1,153
OTHER (EXPENSE) INCOME
Interest expense	(120)	(117)	(238)	(231)
Interest expense - affiliates, net	(14)	(16)	(27)	(31)
Other income (expense), net	16	(2)	25	(1)
Total other expense, net	(118)	(135)	(240)	(263)
INCOME BEFORE INCOME TAX EXPENSE	508	438	1,018	890
Income tax expense	81	170	211	344
NET INCOME	427	268	807	546
Non-affiliate services
OPERATING REVENUES
Total operating revenues	1,393	1,464	2,812	2,950
Affiliate services
OPERATING REVENUES
Total operating revenues	$ 708	$ 669	$ 1,419	$ 1,345