CONSOLIDATED COMBINED STATEMENTS OF COMPREHENSIVE INCOME - USD ($)	12 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Mar. 31, 2018
Statement of Comprehensive Income [Abstract]
Net (loss) income	$ (676,000,000)	$ 72,000,000	$ 208,000,000
Other comprehensive loss, net of taxes:
Actuarial loss on pension plan assets, net of tax benefit of $1, $0 and $0	(2,000,000)	0	0
Change in net unrealized gains (losses) on cash flow hedges:
Net unrealized losses arising during the period, net of tax effect of $18, $10 and $0	(52,000,000)	(29,000,000)	0
Net losses reclassified to earnings, net of tax effect of $3, $2 and $0	8,000,000	6,000,000	0
Other comprehensive loss, net of taxes	(46,000,000)	(23,000,000)	0
Comprehensive (loss) income	$ (722,000,000)	$ 49,000,000	$ 208,000,000