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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, 2018	Mar. 31, 2017	Mar. 31, 2016
United States
Defined Benefit Plan Disclosure [Line Items]
Net actuarial loss (gain)	$ (15)	$ (17)	$ 9
Prior service credit	0	0	0
Amortization of:
Net actuarial loss	(8)	(11)	(44)
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)	(23)	(28)	(35)
Non-U.S. Plans
Defined Benefit Plan Disclosure [Line Items]
Net actuarial loss (gain)	(11)	47	(38)
Prior service credit	(2)	0	(5)
Amortization of:
Net actuarial loss	(6)	(4)	(5)
Prior service credit (cost)	0	2	2
Foreign exchange impact and other	19	(10)	(1)
Total recognized in net periodic benefit cost and other comprehensive loss (income)	$ 0	$ 35	$ (47)

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Other Comprehensive Income Defined Benefit Plans Net Translation Gain Loss Arising During Period Before Tax

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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).

+ References

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-Publisher FASB
-Name Accounting Standards Codification
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Amount, before tax, of gain (loss) for (increase) decrease in value of benefit obligation for change in actuarial assumptions and increase (decrease) in value of plan assets from experience different from that assumed of defined benefit plan, that has not been recognized in net periodic benefit (cost) credit.

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