Revenue recognition - Contract assets and liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Jun. 30, 2019
Revenue from Contract with Customer [Abstract]
Contract assets, current (included within Prepaid expenses and other)	$ 25,427	$ 22,726
Contract assets, noncurrent (included within Investments and other assets)	1,095	1,301
Total contract assets	26,522	24,027
Contract liabilities, current (included within Other accrued liabilities)	(60,839)	(64,668)
Contract liabilities, noncurrent (included within Other liabilities)	(411)	(421)
Total contract liabilities	(61,250)	(65,089)
Net contract liabilities	$ (34,728)	$ (41,062)