Commitments and contingencies - Narrative - Operating Leases (Details) - USD ($) $ in Thousands	12 Months Ended
	Jun. 30, 2019	Jun. 30, 2018		Jun. 30, 2017		Aug. 31, 2017
Operating Leased Assets [Line Items]
Reversal of deferred rent	$ (375)	$ (1,178)	[1]	$ (66)	[1]
Tenant improvement allowance recognition due to lease termination	0	582	[1]	0	[1]
Rent expense	$ 4,400	4,500		$ 4,100
Avaya Sublease
Operating Leased Assets [Line Items]
Term of contract ( in years)						6 years
Renewal term (in years)						3 years
Reversal of deferred rent		538
Tenant improvement allowance recognition due to lease termination		$ 582

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