Share-Based Compensation - Employee Stock Purchase Plan (Details) - USD ($) $ in Millions	12 Months Ended
Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unvested share-based payment awards	$ 303.8
Nonvested awards, total compensation cost not yet recognized, period for recognition	1 year 11 months 1 day
Employee Stock Purchase Plans
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share based compensation arrangement by share based payment award, market price offering date percentage	85.00%
Common stock, capital shares reserved for future issuance (in shares)	35,000,572
Number of shares available for grant (in shares)	10,929,886
Stock issued during period, shares, employee stock purchase plans (in shares)	1,485,477	1,424,440	1,574,568
Stock issued during period, value, employee stock purchase plan	$ 70.0	$ 57.7	$ 55.6
Unvested share-based payment awards	$ 7.2
Nonvested awards, total compensation cost not yet recognized, period for recognition	5 months

Aggregate number of common shares reserved for future issuance.

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Weighted-average period over which cost not yet recognized is expected to be recognized for award under share-based payment arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

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Purchase price of common stock expressed as a percentage of its fair value.

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Number of shares issued during the period as a result of an employee stock purchase plan.

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