Consolidated Statements of Comprehensive Income (Loss) - 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 (loss) income	$ 112	$ (177)	$ (389)	$ 19
Other comprehensive income:
Other comprehensive income	0	0	0	0
Other comprehensive income	0	0	0	0
Total comprehensive income	112	(177)	(389)	19
Total comprehensive income attributable to noncontrolling interests	(1)	(1)	(3)	(3)
Total comprehensive income attributable to partners	$ 111	$ (178)	$ (392)	$ 16