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Pension Benefits - Summary Of Pension Plan Assets Using Fair Value Hierarchy By Asset Class (Details) - USD ($) $ in Millions	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2015
U.S. Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 293	$ 262	$ 298
U.S. Plans | Total
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	293	262
Non-U.S. Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	623	607	$ 612
Non-U.S. Plans | Total
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	623	607
Investment Assets at Fair Value | U.S. Plans | Total
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	93	80
Investment Assets at Fair Value | U.S. Plans | Cash and cash equivalents
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	8	4
Investment Assets at Fair Value | U.S. Plans | Common and preferred stock
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	17	16
Investment Assets at Fair Value | U.S. Plans | Equity commingled funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Investment Assets at Fair Value | U.S. Plans | Government securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	27	12
Investment Assets at Fair Value | U.S. Plans | Corporate bonds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	12	12
Investment Assets at Fair Value | U.S. Plans | Mortgage-backed securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	10	14
Investment Assets at Fair Value | U.S. Plans | Asset-backed securities and other
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	19	22
Investment Assets at Fair Value | U.S. Plans | Fixed income commingled funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Investment Assets at Fair Value | U.S. Plans | Real estate funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Investment Assets at Fair Value | U.S. Plans | Other
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Investment Assets at Fair Value | U.S. Plans | Level 1 | Total
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	25	20
Investment Assets at Fair Value | U.S. Plans | Level 1 | Cash and cash equivalents
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	8	4
Investment Assets at Fair Value | U.S. Plans | Level 1 | Common and preferred stock
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	17	16
Investment Assets at Fair Value | U.S. Plans | Level 1 | Equity commingled funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Investment Assets at Fair Value | U.S. Plans | Level 1 | Government securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Investment Assets at Fair Value | U.S. Plans | Level 1 | Corporate bonds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Investment Assets at Fair Value | U.S. Plans | Level 1 | Mortgage-backed securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Investment Assets at Fair Value | U.S. Plans | Level 1 | Asset-backed securities and other
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Investment Assets at Fair Value | U.S. Plans | Level 1 | Fixed income commingled funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Investment Assets at Fair Value | U.S. Plans | Level 1 | Real estate funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Investment Assets at Fair Value | U.S. Plans | Level 1 | Other
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Investment Assets at Fair Value | U.S. Plans | Level 2 | Total
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	68	60
Investment Assets at Fair Value | U.S. Plans | Level 2 | Cash and cash equivalents
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Investment Assets at Fair Value | U.S. Plans | Level 2 | Common and preferred stock
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Investment Assets at Fair Value | U.S. Plans | Level 2 | Equity commingled funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Investment Assets at Fair Value | U.S. Plans | Level 2 | Government securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	27	12
Investment Assets at Fair Value | U.S. Plans | Level 2 | Corporate bonds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	12	12
Investment Assets at Fair Value | U.S. Plans | Level 2 | Mortgage-backed securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	10	14
Investment Assets at Fair Value | U.S. Plans | Level 2 | Asset-backed securities and other
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	19	22
Investment Assets at Fair Value | U.S. Plans | Level 2 | Fixed income commingled funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Investment Assets at Fair Value | U.S. Plans | Level 2 | Real estate funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Investment Assets at Fair Value | U.S. Plans | Level 2 | Other
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Investment Assets at Fair Value | U.S. Plans | Level 3 | Total
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Investment Assets at Fair Value | U.S. Plans | Level 3 | Cash and cash equivalents
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Investment Assets at Fair Value | U.S. Plans | Level 3 | Common and preferred stock
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Investment Assets at Fair Value | U.S. Plans | Level 3 | Equity commingled funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Investment Assets at Fair Value | U.S. Plans | Level 3 | Government securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Investment Assets at Fair Value | U.S. Plans | Level 3 | Corporate bonds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Investment Assets at Fair Value | U.S. Plans | Level 3 | Mortgage-backed securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Investment Assets at Fair Value | U.S. Plans | Level 3 | Asset-backed securities and other
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Investment Assets at Fair Value | U.S. Plans | Level 3 | Fixed income commingled funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Investment Assets at Fair Value | U.S. Plans | Level 3 | Real estate funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Investment Assets at Fair Value | U.S. Plans | Level 3 | Other
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Investment Assets at Fair Value | Non-U.S. Plans | Total
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	403	429
Investment Assets at Fair Value | Non-U.S. Plans | Cash and cash equivalents
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	2	4
Investment Assets at Fair Value | Non-U.S. Plans | Common and preferred stock
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Investment Assets at Fair Value | Non-U.S. Plans | Equity commingled funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	53	65
Investment Assets at Fair Value | Non-U.S. Plans | Government securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	92	90
Investment Assets at Fair Value | Non-U.S. Plans | Corporate bonds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	199	15
Investment Assets at Fair Value | Non-U.S. Plans | Mortgage-backed securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Investment Assets at Fair Value | Non-U.S. Plans | Asset-backed securities and other
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Investment Assets at Fair Value | Non-U.S. Plans | Fixed income commingled funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	49	131
Investment Assets at Fair Value | Non-U.S. Plans | Real estate funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	8	8
Investment Assets at Fair Value | Non-U.S. Plans | Other
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	116
Investment Assets at Fair Value | Non-U.S. Plans | Level 1 | Total
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	130	121
Investment Assets at Fair Value | Non-U.S. Plans | Level 1 | Cash and cash equivalents
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	2	4
Investment Assets at Fair Value | Non-U.S. Plans | Level 1 | Common and preferred stock
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Investment Assets at Fair Value | Non-U.S. Plans | Level 1 | Equity commingled funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	13	6
Investment Assets at Fair Value | Non-U.S. Plans | Level 1 | Government securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	24	22
Investment Assets at Fair Value | Non-U.S. Plans | Level 1 | Corporate bonds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	69	1
Investment Assets at Fair Value | Non-U.S. Plans | Level 1 | Mortgage-backed securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Investment Assets at Fair Value | Non-U.S. Plans | Level 1 | Asset-backed securities and other
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Investment Assets at Fair Value | Non-U.S. Plans | Level 1 | Fixed income commingled funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	20	67
Investment Assets at Fair Value | Non-U.S. Plans | Level 1 | Real estate funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	2	0
Investment Assets at Fair Value | Non-U.S. Plans | Level 1 | Other
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	21
Investment Assets at Fair Value | Non-U.S. Plans | Level 2 | Total
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	257	300
Investment Assets at Fair Value | Non-U.S. Plans | Level 2 | Cash and cash equivalents
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Investment Assets at Fair Value | Non-U.S. Plans | Level 2 | Common and preferred stock
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Investment Assets at Fair Value | Non-U.S. Plans | Level 2 | Equity commingled funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	40	59
Investment Assets at Fair Value | Non-U.S. Plans | Level 2 | Government securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	68	68
Investment Assets at Fair Value | Non-U.S. Plans | Level 2 | Corporate bonds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	120	14
Investment Assets at Fair Value | Non-U.S. Plans | Level 2 | Mortgage-backed securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Investment Assets at Fair Value | Non-U.S. Plans | Level 2 | Asset-backed securities and other
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Investment Assets at Fair Value | Non-U.S. Plans | Level 2 | Fixed income commingled funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	29	64
Investment Assets at Fair Value | Non-U.S. Plans | Level 2 | Real estate funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Investment Assets at Fair Value | Non-U.S. Plans | Level 2 | Other
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	95
Investment Assets at Fair Value | Non-U.S. Plans | Level 3 | Total
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	16	8
Investment Assets at Fair Value | Non-U.S. Plans | Level 3 | Cash and cash equivalents
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Investment Assets at Fair Value | Non-U.S. Plans | Level 3 | Common and preferred stock
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Investment Assets at Fair Value | Non-U.S. Plans | Level 3 | Equity commingled funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Investment Assets at Fair Value | Non-U.S. Plans | Level 3 | Government securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Investment Assets at Fair Value | Non-U.S. Plans | Level 3 | Corporate bonds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	10	0
Investment Assets at Fair Value | Non-U.S. Plans | Level 3 | Mortgage-backed securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Investment Assets at Fair Value | Non-U.S. Plans | Level 3 | Asset-backed securities and other
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Investment Assets at Fair Value | Non-U.S. Plans | Level 3 | Fixed income commingled funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Investment Assets at Fair Value | Non-U.S. Plans | Level 3 | Real estate funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	6	8
Investment Assets at Fair Value | Non-U.S. Plans | Level 3 | Other
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Assets held at NAV practical expedient (1) | U.S. Plans | Equity commingled funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	131	165
Assets held at NAV practical expedient (1) | U.S. Plans | Fixed income commingled funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	59	0
Assets held at NAV practical expedient (1) | U.S. Plans | Real estate funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	10	17
Assets held at NAV practical expedient (1) | U.S. Plans | Other
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Assets held at NAV practical expedient (1) | Non-U.S. Plans | Equity commingled funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	94	91
Assets held at NAV practical expedient (1) | Non-U.S. Plans | Fixed income commingled funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	53	56
Assets held at NAV practical expedient (1) | Non-U.S. Plans | Real estate funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	13	16
Assets held at NAV practical expedient (1) | Non-U.S. Plans | Other
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 60	$ 15

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+ References

No definition available.

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+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 30
-Section 35
-Paragraph 50
-URI http://asc.fasb.org/extlink&oid=64937038&loc=d3e12355-114930

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=65897934&loc=d3e1928-114920

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Plan Assets
-URI http://asc.fasb.org/extlink&oid=6749337

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Plan Assets
-URI http://asc.fasb.org/extlink&oid=6520858

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