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

Stock-Based Compensation - Summary of Stock Options Available for Grant (Detail)

v3.8.0.1
Stock-Based Compensation - Summary of Stock Options Available for Grant (Detail) - shares
12 Months Ended
Mar. 31, 2018
Mar. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant [Roll Forward]    
Shares Available for Grant, Beginning balance 27,238,814 28,418,808
Granted (1,779,904) (1,179,994)
Shares Available for Grant, Ending balance 25,458,910 27,238,814