CONSOLIDATED COMBINED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Millions	5 Months Ended	12 Months Ended
	Mar. 31, 2017	Mar. 31, 2019	Mar. 31, 2018	Oct. 31, 2016
Statement of Comprehensive Income [Abstract]
Net income	$ 36	$ 72	$ 208	$ 80
Other comprehensive income (loss), net of taxes:
Cash flow hedge adjustment, net of tax benefit of $8, $0, $0 and $0	0	(23)	0	0
Comprehensive income	$ 36	$ 49	$ 208	$ 80