Income Taxes - Gross Unrecognized Tax Benefits (Details) - USD ($) $ in Millions	12 Months Ended
Mar. 31, 2019	Mar. 31, 2018
Reconciliation of Unrecognized Tax Benefits [Roll Forward]
Balance at beginning of period	$ 15.6	$ 15.0
Additions based on tax positions related to the current year	7.7	0.8
Additions for tax positions of prior years	4.7	0.0
Reductions for tax positions of prior years	0.0	0.0
Settlements	(2.3)	0.0
Reductions due to lapse of applicable statute of limitations	(7.1)	(0.6)
Cumulative translation adjustment, decrease	(0.3)
Cumulative translation adjustment, increase		0.4
Balance at end of period	$ 18.3	$ 15.6

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

No definition available.

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- Definition

Amount of unrecognized tax benefits.

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Amount of decrease in unrecognized tax benefits resulting from foreign currency translation.

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Amount of increase in unrecognized tax benefits resulting from tax positions that have been or will be taken in current period tax return.

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