Pension Benefits - Schedule Of Net Periodic Expense For Pension Plans (Details) - USD ($) $ in Millions	12 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2015
U.S. Plans
Defined Benefit Plan Disclosure [Line Items]
Service cost - benefits earned during the year	$ 5	$ 4	$ 1
Interest cost on projected benefit obligation	13	18	19
Expected return on assets	(15)	(19)	(21)
Amortization of unrecognized actuarial loss and prior service costs	11	42	19
Curtailment/settlement loss (gain)	0	2	0
Net periodic expense	14	47	18
Non-U.S. Plans
Defined Benefit Plan Disclosure [Line Items]
Service cost - benefits earned during the year	15	20	16
Interest cost on projected benefit obligation	23	24	34
Expected return on assets	(26)	(30)	(30)
Amortization of unrecognized actuarial loss and prior service costs	4	3	3
Curtailment/settlement loss (gain)	(2)	0	6
Net periodic expense	$ 14	$ 17	$ 29