Employee Retirement Plans (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2016
Australia Plan [Member] | Foreign Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Percentage of contribution by the company to the retirement plans	9.50%
Total contribution by the company to the employee retirement plans	$ 10.5	$ 9.9	$ 9.1
United States Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Percentage of contribution by the company to the retirement plans	4.00%
Total contribution by the company to the employee retirement plans	$ 5.0	4.3	3.3
Singapore Plan [Member] | Foreign Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Percentage of contribution by the company to the retirement plans	17.00%
Total contribution by the company to the employee retirement plans	$ 2.2	$ 1.7	$ 1.4