Summary of business and significant accounting policies - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Mar. 31, 2020	Mar. 31, 2019
Disaggregation of Revenue [Line Items]
Total revenue	$ 64,496	$ 48,540	$ 205,000	$ 144,952
Product
Disaggregation of Revenue [Line Items]
Total revenue	52,106	41,723	169,639	124,050
Services
Disaggregation of Revenue [Line Items]
Total revenue	12,390	6,817	35,361	20,902
Point in Time | On-board automotive navigation solutions
Disaggregation of Revenue [Line Items]
Total revenue	52,106	41,723	169,639	124,050
Over Time | Brought-in automotive navigation solutions (over time)
Disaggregation of Revenue [Line Items]
Total revenue	9,632	4,250	24,641	12,272
Over Time | Automotive maintenance and support and other (over time)
Disaggregation of Revenue [Line Items]
Total revenue	153	42	3,028	697
Over Time | Mobile navigation services (over time)
Disaggregation of Revenue [Line Items]
Total revenue	$ 2,605	$ 2,525	$ 7,692	$ 7,933