Segment information - Reconciliation of Segment Results to Income Before Tax (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Segment Reporting Information [Line Items]
Segment Adjusted EBITDA	$ 9,437	$ 11,085	$ 18,289	$ 22,552
Stock-based compensation costs	(200)	(300)	(100)	(700)
Net interest (expense)/income	(223)	(141)	264	(219)
Income before income tax expense	1,962	3,788	5,774	7,911
Operating Segments
Segment Reporting Information [Line Items]
Segment Adjusted EBITDA	9,437	11,085	18,289	22,552
Corporate and Eliminations
Segment Reporting Information [Line Items]
Corporate and consolidation entries	(2,778)	(2,474)	(4,952)	(4,850)
Segment Reconciling Items
Segment Reporting Information [Line Items]
Operating lease costs	(301)	(373)	(635)	(780)
Product development costs	(349)	(335)	(692)	(698)
Depreciation and amortization	(3,450)	(3,668)	(7,196)	(7,347)
Impairment of long-lived assets	0	(28)	0	(28)
Stock-based compensation costs	(243)	(330)	(51)	(694)
Restructuring costs	0	(51)	0	(52)
Net profit on sale of property, plant and equipment	0	43	33	43
Net foreign exchange gains/(losses)	653	60	1,498	(16)
Net interest (expense)/income	(223)	(141)	264	(219)
Acquisition-related costs	$ (784)	$ 0	$ (784)	$ 0