Stock-Based Compensation - Schedule of Stock-Based Compensation Expense (Detail) - USD ($) $ in Millions |
12 Months Ended | ||
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Mar. 31, 2019 |
Mar. 31, 2018 |
Mar. 31, 2017 |
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| Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items] | |||
| Total stock-based compensation expense | $ 11.9 | $ 16.7 | $ 14.7 |
| Liability Awards Expense [Member] | |||
| Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items] | |||
| Total stock-based compensation expense | (0.6) | 5.6 | 5.4 |
| Equity Awards Expense [Member] | |||
| Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items] | |||
| Total stock-based compensation expense | $ 12.5 | $ 11.1 | $ 9.3 |
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- Definition Amount of expense for employee benefit and equity-based compensation. No definition available.
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- Definition 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. No definition available.
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