Balance sheet information - Goodwill and Intangible Assets, Net (Details) - USD ($) $ in Thousands	12 Months Ended
	Jun. 30, 2019	Jun. 30, 2018		Jun. 30, 2017
Balance Sheet Related Disclosures [Abstract]
Acquired developed technology	$ 13,875	$ 13,875
Less accumulated amortization	(12,494)	(11,491)
Intangible assets, net	1,381	2,384
Amortization expense for intangibles	1,000	1,100		$ 1,100
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
Amortization expense for intangible assets in fiscal 2020	872
Amortization expense for intangible assets in fiscal 2021	509
Goodwill [Roll Forward]
Goodwill	28,662
Impairment	(2,556)	(2,666)	[1]	$ 0	[1]
Goodwill	26,106	28,662
Automotive
Goodwill [Roll Forward]
Goodwill	14,320
Impairment	0
Goodwill	14,320	14,320
Advertising
Goodwill [Roll Forward]
Goodwill	14,342
Impairment	(2,556)
Goodwill	$ 11,786	14,342
Mobile Navigation
Goodwill [Roll Forward]
Impairment		$ (2,700)

[1] See Note 1 for a summary of adjustments.