Derivative Financial Instruments - Fair Values of Derivative Assets and Liabilities (Details) - USD ($) $ in Millions	Jun. 30, 2018	Mar. 31, 2018
Forward foreign currency exchange contracts
Derivative [Line Items]
Assets subject to master netting arrangements	$ 3.8	$ 0.0
Liabilities subject to master netting arrangements	0.1	7.7
Derivative assets, net	3.7	0.0
Derivative liabilities, net	0.0	7.7
Net investment hedges
Derivative [Line Items]
Assets subject to master netting arrangements	4.8	0.0
Liabilities subject to master netting arrangements	0.0	0.0
Derivative assets, net	4.8	0.0
Derivative liabilities, net	$ 0.0	$ 0.0

Fair value, after the effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets not subject to a master netting arrangement and not elected to be offset.

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Fair value, after effects of master netting arrangements, of financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset offset against an obligation to return collateral. Includes assets not subject to a master netting arrangement and not elected to be offset.

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Fair value, after effects of master netting arrangements, of financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset offset against the right to receive collateral. Includes liabilities not subject to a master netting arrangement and not elected to be offset.

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Fair value, after the effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes liabilities not subject to a master netting arrangement and not elected to be offset.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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