Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Statement of Comprehensive Income [Abstract]
Net (loss) income	$ 48	$ 120	$ (501)	$ 196
Other comprehensive income:
Other comprehensive income	0	0	0	0
Other comprehensive income	0	0	0	0
Total comprehensive income	48	120	(501)	196
Total comprehensive income attributable to noncontrolling interests	(1)	(1)	(2)	(2)
Total comprehensive income attributable to partners	$ 47	$ 119	$ (503)	$ 194