CONDENSED CONSOLIDATED COMBINED STATEMENTS OF COMPREHENSIVE INCOME (unaudited) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2018	Dec. 31, 2017
Statement of Comprehensive Income [Abstract]
Net income	$ 38	$ 104	$ 91	$ 176
Other comprehensive income (loss), net of taxes:
Cash flow hedge adjustments, net of tax	(18)	0	(13)	0
Comprehensive income	$ 20	$ 104	$ 78	$ 176