Accrued expenses and other liabilities - Schedule of Accrued Expenses (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Mar. 31, 2019
Current:
Product warranties	$ 601	$ 757
Maintenance	357	477
Employee-related accruals	5,296	8,101
Lease liabilities	$ 1,094	$ 750
Lease liabilities [Extensible List]	us-gaap:LiabilitiesCurrentAbstract	us-gaap:LiabilitiesCurrentAbstract
Accrued income tax payable	$ 736	$ 173
Other accruals	6,755	7,165
Total current	14,839	17,423
Non-current:
Lease liabilities	$ 5,413	$ 2,161
Lease liabilities [Extensible List]	us-gaap:LiabilitiesNoncurrentAbstract	us-gaap:LiabilitiesNoncurrentAbstract
Other liabilities	$ 247	$ 277
Total non-current	$ 5,660	$ 2,438