Revenue from contracts with customers - Summary of Recognized Amortization Expense (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Capitalized Contract Cost [Line Items]
Amortization recognized during the quarter	$ (857)	$ (782)	$ (1,767)	$ (1,475)
Cost of Revenue
Capitalized Contract Cost [Line Items]
Amortization recognized during the quarter	(616)	(563)	(1,291)	(1,048)
Sales and Marketing
Capitalized Contract Cost [Line Items]
Amortization recognized during the quarter	$ (241)	$ (219)	$ (476)	$ (427)