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Pension Benefits - Schedule Of Other Changes In Accumulated Other Comprehensive Income (Details) - Pension Plans, Defined Benefit - USD ($) $ in Millions	12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2017
United States
Defined Benefit Plan Disclosure [Line Items]
Net actuarial loss (gain)	$ 8	$ (15)	$ (17)
Prior service credit	0	0	0
Amortization of:
Net actuarial loss	(9)	(8)	(11)
Prior service credit (cost)	0	0	0
Foreign exchange impact and other	0	0	0
Total recognized in net periodic benefit cost and other comprehensive loss (income)	(1)	(23)	(28)
Non-U.S. Plans
Defined Benefit Plan Disclosure [Line Items]
Net actuarial loss (gain)	42	(11)	47
Prior service credit	0	(2)	0
Amortization of:
Net actuarial loss	(5)	(6)	(4)
Prior service credit (cost)	0	0	2
Foreign exchange impact and other	(12)	19	(10)
Total recognized in net periodic benefit cost and other comprehensive loss (income)	$ 25	$ 0	$ 35

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Amount, before tax, of cost (credit) of benefit change attributable to participants' prior service from plan amendment or plan initiation of defined benefit plan, that has not been recognized in net periodic benefit cost (credit).

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