CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
OPERATING REVENUE
Total operating revenue	$ 8,493	$ 8,550	$ 8,910
OPERATING EXPENSES
Cost of services and products (exclusive of depreciation and amortization)	2,767	2,881	2,934
Selling, general and administrative	799	925	1,020
Operating expenses - affiliates	831	848	941
Depreciation and amortization	1,436	1,583	1,691
Total operating expenses	5,833	6,237	6,586
OPERATING INCOME	2,660	2,313	2,324
OTHER (EXPENSE) INCOME
Interest expense	(448)	(465)	(478)
Interest expense - affiliates, net	(57)	(63)	(59)
Other income (expense), net	4	6	(24)
Total other expense, net	(501)	(522)	(561)
INCOME BEFORE INCOME TAX EXPENSE	2,159	1,791	1,763
Income tax expense	494	134	678
NET INCOME	1,665	1,657	1,085
Non-Affiliate Services
OPERATING REVENUE
Total operating revenue	5,558	5,831	6,247
Affiliate services
OPERATING REVENUE
Total operating revenue	$ 2,935	$ 2,719	$ 2,663