Revenue Recognition - Revenue by geographic region (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2018
Disaggregation of Revenue [Line Items]
Revenues from contracts	$ 3,160,603	$ 3,702,432	$ 3,497,974	$ 3,334,511	$ 3,681,467	$ 3,687,518	$ 3,472,045	$ 3,479,294	$ 13,695,520	$ 14,320,324	$ 14,302,392
North America
Disaggregation of Revenue [Line Items]
Revenues from contracts									9,166,773	9,318,195	$ 8,978,490
Europe
Disaggregation of Revenue [Line Items]
Revenues from contracts									2,596,125	2,968,971
Asia Pacific
Disaggregation of Revenue [Line Items]
Revenues from contracts									1,790,032	1,855,831
Latin America
Disaggregation of Revenue [Line Items]
Revenues from contracts									$ 142,590	$ 177,327