Net Loss Per Share - Summary of Number of Ordinary Shares Excluded from Computation of Earnings Per Share (Detail) - shares	Mar. 31, 2016	Mar. 31, 2015	Mar. 31, 2014
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Ordinary shares issuable excluded from computation of earnings per share	2,853,158	6,060,012	9,813,870
Exercise Of Options To Purchase Ordinary Shares
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Ordinary shares issuable excluded from computation of earnings per share	1,589,938	1,208,118	779,462
Restricted Share Units Awarded, Including Multi-Year Performance
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Ordinary shares issuable excluded from computation of earnings per share	237,695
Exercise Of Warrants At $16.14 Per Share
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Ordinary shares issuable excluded from computation of earnings per share	111,525
Exercise Of Warrants At $9.37 Per Share
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Ordinary shares issuable excluded from computation of earnings per share	64,000	64,000
Exercise Of Warrants At $8.80 Per Share
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Ordinary shares issuable excluded from computation of earnings per share		3,937,894
Exercise Of Pre-Funded Warrants At $0.01 Per Share
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Ordinary shares issuable excluded from computation of earnings per share	850,000	850,000
A Preference Shares [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Ordinary shares issuable excluded from computation of earnings per share			4,070,385
B Preference Shares [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Ordinary shares issuable excluded from computation of earnings per share			4,666,690
C Preference Shares [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Ordinary shares issuable excluded from computation of earnings per share			297,333