CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2018	Jun. 30, 2020	Jun. 30, 2019
Statement of Comprehensive Income [Abstract]
Net income	$ 61	$ 57	$ 155	$ 157
Other comprehensive income
Change in fair value of cash flow hedges (Note 13)	(2)	(9)	(15)	(14)
Reclassification to net income of (gains) and losses on cash flow hedges (Note 13)	2	1	2	1
Comprehensive income	61	49	142	144
Comprehensive income attributable to non-controlling interests	4	2	10	9
Comprehensive income attributable to controlling interests	$ 57	$ 47	$ 132	$ 135