Revenue recognition - Revenue by geographic region (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2021	Mar. 31, 2020
Disaggregation of Revenue [Line Items]
Revenues from contracts	$ 3,746,326	$ 3,702,432	$ 10,388,771	$ 10,534,917
North America
Disaggregation of Revenue [Line Items]
Revenues from contracts	2,354,251	2,507,566	6,598,238	7,107,655
Europe
Disaggregation of Revenue [Line Items]
Revenues from contracts	788,498	726,577	2,087,030	2,018,301
Asia Pacific
Disaggregation of Revenue [Line Items]
Revenues from contracts	561,274	430,500	1,586,375	1,292,054
Latin America
Disaggregation of Revenue [Line Items]
Revenues from contracts	$ 42,303	$ 37,789	$ 117,128	$ 116,907