For an unclassified balance sheet, the amount due from customers or clients for goods or services that have been delivered or sold in the normal course of business, reduced to their estimated net realizable fair value by an allowance established by the entity of the amount it deems uncertain of collection.

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Accounting Pronouncements (Details) - USD ($) $ in Millions	Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2016
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Adoption of ASU 2016-09, cumulative adjustment			$ 49.6
Increase to other current assets	$ 55.9	$ 58.9
Decrease to inventories	(476.2)	(417.2)
Decrease to deferred taxes	(105.6)	(340.2)
Increase to retained earnings	1,397.3	$ 1,479.4
Accounting Standards Update 2016-09, Forfeiture Rate Component, Share-based Payment Award Component \| New Accounting Pronouncement, Early Adoption, Effect
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Deferred income tax assets, net			2.3
Accounting Standards Update 2016-09, Excess Tax Benefit Component \| New Accounting Pronouncement, Early Adoption, Effect
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Deferred income tax assets, net			47.2
Retained Earnings
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Adoption of ASU 2016-09, cumulative adjustment			47.6
Retained Earnings \| Accounting Standards Update 2016-09, Forfeiture Rate Component \| New Accounting Pronouncement, Early Adoption, Effect
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Adoption of ASU 2016-09, cumulative adjustment			2.0
Retained Earnings \| Accounting Standards Update 2016-09, Forfeiture Rate Component, Share-based Payment Award Component \| New Accounting Pronouncement, Early Adoption, Effect
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Adoption of ASU 2016-09, cumulative adjustment			2.3
Retained Earnings \| Accounting Standards Update 2016-09, Excess Tax Benefit Component \| New Accounting Pronouncement, Early Adoption, Effect
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Adoption of ASU 2016-09, cumulative adjustment			47.2
Retained Earnings \| Accounting Standards Update 2016-16 \| New Accounting Pronouncement, Early Adoption, Effect
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Adoption of ASU 2016-09, cumulative adjustment	1,600.0
Additional Paid-in Capital \| Accounting Standards Update 2016-09, Forfeiture Rate Component \| New Accounting Pronouncement, Early Adoption, Effect
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Adoption of ASU 2016-09, cumulative adjustment			$ (2.0)
Calculated under Revenue Guidance in Effect before Topic 606
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Elimination of deferred revenue	334.0
Minimum \| Difference between Revenue Guidance in Effect before and after Topic 606 \| Accounting Standards Update 2014-09
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Decrease to accounts receivable	41.0
Increase to accrued liabilities	10.0
Increase to other current assets	14.0
Decrease to inventories	4.0
Decrease to deferred taxes	38.0
Increase to retained earnings	219.0
Maximum \| Difference between Revenue Guidance in Effect before and after Topic 606 \| Accounting Standards Update 2014-09
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Decrease to accounts receivable	51.0
Increase to accrued liabilities	14.0
Increase to other current assets	18.0
Decrease to inventories	6.0
Decrease to deferred taxes	58.0
Increase to retained earnings	$ 259.0