Summary of business and significant accounting policies - Deferred Costs (Details) - USD ($) $ in Thousands	12 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Contract with Customer Asset [Roll Forward]
Balance, beginning of period	$ 79,802	$ 58,425
Content licensing costs incurred	113,030	123,493
Customized software development costs incurred	4,015	2,537
Less: cost of revenue recognized	(116,178)	(104,653)
Balance, end of period	80,669	79,802
Content
Contract with Customer Asset [Roll Forward]
Balance, beginning of period	71,466	48,946
Content licensing costs incurred	113,030	123,493
Customized software development costs incurred	0	0
Less: cost of revenue recognized	(110,898)	(100,973)
Balance, end of period	73,598	71,466
Development
Contract with Customer Asset [Roll Forward]
Balance, beginning of period	8,336	9,479
Content licensing costs incurred	0	0
Customized software development costs incurred	4,015	2,537
Less: cost of revenue recognized	(5,280)	(3,680)
Balance, end of period	$ 7,071	$ 8,336