Financing Arrangement (Schedule Of Interest Expense Related To Notes) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2020	Dec. 31, 2019
Debt Instruments [Abstract]
Amortization of debt issuance costs	$ (1)	$ 0	$ (2)	$ (1)
Coupon interest expense	(10)	(10)	(31)	(31)
Total interest expense	$ (11)	$ (10)	$ (33)	$ (32)