Fair Value Measurements - Summary of Change in Estimated Fair Value of Ordinary and Preference Share Warrant Liabilities (Detail) - USD ($) $ in Thousands		12 Months Ended
	Oct. 26, 2015	Mar. 31, 2016	Mar. 31, 2015
Fair Value Disclosures [Abstract]
Warrant at fair value, Beginning balance		$ 31,011	$ 421
Transfer of liability to shareholders' equity upon the conversion of the preference share warrant to a warrant in respect of ordinary shares			(421)
Issue of ordinary share warrants as part of the company's initial public offering			8,529
Change in financial liability for share warrants		(15,857)	22,966
Exercise of warrants	$ (35,100)		(484)
Exercise and expiry of warrants		$ (15,154)
Warrant at fair value, Ending balance			$ 31,011