Revenue recognition - Revenue by geographic region (Details) - USD ($) $ in Thousands	3 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Disaggregation of Revenue [Line Items]
Revenues from contracts	$ 3,230,540	$ 3,334,511
North America
Disaggregation of Revenue [Line Items]
Revenues from contracts	2,096,165	2,255,751
Europe
Disaggregation of Revenue [Line Items]
Revenues from contracts	615,572	639,138
Asia Pacific
Disaggregation of Revenue [Line Items]
Revenues from contracts	485,148	397,714
Latin America
Disaggregation of Revenue [Line Items]
Revenues from contracts	$ 33,655	$ 41,908