Annual and transition report of foreign private issuers pursuant to Section 13 or 15(d)

Stock-Based Compensation - Schedule of Stock-Based Compensation Expense (Detail)

v3.20.1
Stock-Based Compensation - Schedule of Stock-Based Compensation Expense (Detail) - USD ($)
$ in Millions
12 Months Ended
Mar. 31, 2020
Mar. 31, 2019
Mar. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]      
Total stock-based compensation expense $ 13.1 $ 11.9 $ 16.7
Liability Awards Expense [Member]      
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]      
Total stock-based compensation expense 2.8 (0.6) 5.6
Equity Awards Expense [Member]      
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]      
Total stock-based compensation expense $ 10.3 $ 12.5 $ 11.1