Retirement Benefits - Assumptions used to measure benefit obligations (Details)	Jun. 30, 2017	Jun. 30, 2016
Domestic Defined Benefit Plan
Defined Benefit Plan Disclosure [Line Items]
Discount rate	3.64%	3.33%
Average increase in compensation	3.89%	5.02%
Minimum | Non-U.S. defined benefit plans
Defined Benefit Plan Disclosure [Line Items]
Discount rate	0.30%	0.23%
Average increase in compensation	2.00%	2.00%
Maximum | Non-U.S. defined benefit plans
Defined Benefit Plan Disclosure [Line Items]
Discount rate	7.57%	7.75%
Average increase in compensation	5.50%	5.50%