Credit risk related to accounts receivables - Schedule of Movements in the Allowance for Doubtful Debts (Details) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Mar. 31, 2018
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Opening balance	$ 2,719	$ 1,482
Bad debt provision	3,941	2,098	$ 1,858
Write-offs, net of recoveries	(2,655)	(572)
Foreign currency translation differences	(704)	(289)
Closing balance	3,602	$ 2,719	$ 1,482
Accounting Standards Update [Extensible List]		us-gaap:AccountingStandardsUpdate201613Member
Cumulative Effect, Period of Adoption, Adjustment
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Opening balance	301
Closing balance		$ 301
Cumulative Effect, Period of Adoption, Adjusted Balance
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Opening balance	$ 3,020
Closing balance		$ 3,020