CONDENSED CONSOLIDATED COMBINED STATEMENTS OF COMPREHENSIVE INCOME (unaudited) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Statement of Comprehensive Income [Abstract]
Net income		$ 24	$ 40	$ 53	$ 72
Other comprehensive income, net of taxes:
Cash flow hedges adjustments, net of tax	[1]	6	0	5	0
Comprehensive income		$ 30	$ 40	$ 58	$ 72

[1] Tax expense related to cash flow hedge adjustments was not material for the three and six months ended September 30, 2018, respectively.