Consolidated Statement of Comprehensive Income - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Statement of Comprehensive Income [Abstract]
Net income	$ 216	$ 237	$ 697	$ 668
Defined benefit plans
Plan sponsored by equity affiliates, net of income taxes	0	0	0	0
Other comprehensive income	0	0	0	0
Comprehensive Income	216	237	697	668
Less: Comprehensive income attributable to noncontrolling interest	10	0	10	0
Comprehensive Income Attributable to the Partnership	$ 206	$ 237	$ 687	$ 668