Additional Financial Information (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2017
Additional Financial Information [Abstract]
Restricted cash	$ 0.0	$ 0.0
Provision for doubtful accounts receivable	5.4	7.5
Reserve for returns and allowances on accounts receivable		56.2
Interest paid	146.7	119.7	$ 79.8
Income Taxes Paid (Received), Net	13.5	$ (20.3)	$ 14.3
Trade Accounts Receivable
Transfer of Financial Assets Accounted for as Sales [Line Items]
Receivables monetized, amount derecognized	473.9
Cash proceeds from transfer of receivables	469.2
Loss recorded	4.7
Derecognized accounts receivable fro which the Company continues to service, amount outstanding	$ 350.6

Additional Financial Information [Abstract]

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Reserve for returns represent a valuation allowance for the amount of products sold that the entity expects to be returned by the purchaser. Allowances on accounts receivable represent a valuation allowance for receivables due a company that are expected to be uncollectible.

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For an unclassified balance sheet, a valuation allowance for receivables due a company that are expected to be uncollectible.

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Amount of transferred financial assets in which the transferor has continuing involvement with the assets underlying the transaction that have been derecognized. Continuing involvement includes, but is not limited to, servicing, recourse, and restrictions on transferor's interests in transferred financial assets.

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Reflects the net positive or negative amount derived from subtracting from net proceeds of sale, the carrying amounts, net of allocated reserves, of accounts receivable transferred to a third party in a transaction that qualifies for sales treatment.

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The amount of cash paid during the current period to foreign, federal, state, and local authorities as taxes on income, net of any cash received during the current period as refunds for the overpayment of taxes.

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Amount of cash paid for interest, including, but not limited to, capitalized interest and payment to settle zero-coupon bond attributable to accreted interest of debt discount and debt instrument with insignificant coupon interest rate in relation to effective interest rate of borrowing attributable to accreted interest of debt discount; classified as operating and investing activities.

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Amount of cash and cash equivalents restricted as to withdrawal or usage, classified as current. Cash includes, but is not limited to, currency on hand, demand deposits with banks or financial institutions, and other accounts with general characteristics of demand deposits. Cash equivalents include, but are not limited to, short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

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Amount of derecognized financial assets from transactions which comprise an initial transfer and an agreement entered into in contemplation of the initial transfer resulting in retention of substantially all of the exposure to the economic return throughout the term of the transaction, at the date of derecognition.

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Amount, before counterparty netting, of cash proceeds received in transfers of derecognized financial assets from transactions which comprise an initial transfer and an agreement entered into in contemplation of the initial transfer resulting in retention of substantially all of the exposure to the economic return throughout the term of the transaction.

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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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