Consolidated Balance Sheet Detail - Summary of Accrued Expenses and Other Current Liabilities (Detail) - USD ($) $ in Thousands	Sep. 30, 2017	Mar. 31, 2017
Payables And Accruals [Abstract]
Accrued legal and professional fees	$ 299	$ 449
Accrued interest	4,625	4,640
Goods received not invoiced	1,292	932
Accrued capital expenditure	5,596	1,387
Accrued development expenditure	4,308	4,187
Other accrued expenses	1,744	1,914
Total accrued expenses and other current liabilities	$ 17,864	$ 13,509