CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
OPERATING REVENUE
Total operating revenue	$ 1,730	$ 1,801	$ 5,246	$ 5,518
OPERATING EXPENSES
Cost of services and products (exclusive of depreciation and amortization)	426	528	1,305	1,491
Selling, general and administrative	36	128	249	410
Operating expenses—affiliates	177	198	561	557
Depreciation and amortization	232	330	780	985
Total operating expenses	871	1,184	2,895	3,443
OPERATING INCOME	859	617	2,351	2,075
OTHER (EXPENSE) INCOME
Interest expense	(47)	(69)	(142)	(219)
Interest expense—affiliate, net	(25)	(18)	(87)	(50)
Other expense, net	(3)	(18)	(7)	(31)
Total other expense, net	(75)	(105)	(236)	(300)
INCOME BEFORE INCOME TAX EXPENSE	784	512	2,115	1,775
Income tax expense	202	133	542	463
NET INCOME	582	379	1,573	1,312
Non-affiliate services
OPERATING REVENUE
Total operating revenue	1,135	1,200	3,452	3,642
Affiliate Services [Member]
OPERATING REVENUE
Total operating revenue	$ 595	$ 601	$ 1,794	$ 1,876