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

Stock-Based Compensation - Additional Information (Detail)

v3.20.1
Stock-Based Compensation - Additional Information (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 [Line Items]      
Unrecognized compensation cost related to stock-based compensation cost $ 9.7    
Estimated weighted average amortization, period of recognition 1 year 10 months 24 days    
Restricted stock units outstanding (in shares) 3,162,437 4,261,508 4,137,592
Restricted stock units granted (in shares) 800,437 1,714,094  
Restricted stock units vested (in shares) 874,835 745,787  
Unvested restricted stock units cancelled (in shares) 1,024,673 844,391  
Average closing price period 20 days 20 days  
Restricted Stock Units Service Vesting [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Restricted stock units granted (in shares) 24,006 617,793  
Restricted stock units vested (in shares) 304,591 242,964  
Restricted Stock Units Performance Vesting [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Restricted stock units granted (in shares) 273,258 383,182  
Restricted stock units vested (in shares) 207,271    
Unvested restricted stock units cancelled (in shares) 169,816    
Restricted Stock Units (Market Condition) [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Restricted stock units vested (in shares) 362,973 218,473  
Long Term Incentive Award [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
LTI units granted (in shares) 458,484 456,995  
Restricted stock units vested (in shares) 129,549 153,667  
2001 Plan [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Issue of shares authorized (in shares) 45,077,100    
Percentage of grants exercised after first year (as percent) 25.00%    
Percentage of grants exercised after second year (as percent) 25.00%    
Percentage of grants exercised after third year (as percent) 50.00%    
Restricted stock units outstanding (in shares) 520,632    
Long-Term Incentive Plan 2006 [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Restricted stock units outstanding (in shares) 2,641,805    
LTI units granted (in shares) 14,347,871