Retirement Benefits - Assumptions used to measure periodic benefit cost (Details) - Pension Plans, Defined Benefit	12 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2017
U.S. defined benefit plan
Assumptions used to measure net periodic benefit cost
Discount rate	4.01%	3.64%	3.33%
Average increase in compensation	3.65%	3.89%	5.02%
Expected return on plan assets	7.00%	7.50%	7.50%
Non-U.S. defined benefit plans | Minimum
Assumptions used to measure net periodic benefit cost
Discount rate	0.30%	0.30%	0.23%
Average increase in compensation	1.75%	2.00%	2.00%
Expected return on plan assets	1.00%	1.00%	1.00%
Non-U.S. defined benefit plans | Maximum
Assumptions used to measure net periodic benefit cost
Discount rate	3.37%	7.57%	7.75%
Average increase in compensation	5.50%	5.50%	5.50%
Expected return on plan assets	5.75%	5.75%	5.75%