Pension and Other Postretirement Benefits - Narrative (Details) - USD ($)	12 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2016
Defined Benefit Plan Disclosure [Line Items]
Eligible Age for Availing Postretirement Healthcare Benefits	55
Years of Service	10
Defined Contribution Plan [Abstract]
Defined Contribution Plan, Cost	$ 19,600,000	$ 15,800,000	$ 17,200,000
Pension plans contribution [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Benefit Obligation, (Increase) Decrease for Settlement	(2,935,000)	(7,439,000)
Accumulated Benefit Obligation for all Defined Benefit Pension Plans	902,100,000	940,900,000
Net Periodic Pension Cost	(16,518,000)	(16,290,000)	(8,647,000)
Special termination benefit charge	0	98,000	334,000
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Settlement	(626,000)	(379,000)	(227,000)
Projected Benefit Payments for 2019	49,300,000
Projected Benefit Payments for 2020	50,100,000
Projected Benefit Payments for 2021	51,800,000
Projected Benefit Payments for 2022	52,300,000
Projected Benefit Payments for 2023	54,100,000
Projected Benefit Payments for 2024 through 2028	280,100,000
Accumulated Other Comprehensive Loss Expected to be Recognized in Net Periodic Pension Cost during 2019 related to Net Actuarial Losses	6,775,854
Accumulated Other Comprehensive Loss Expected to be Recognized in Net Periodic Pension Cost during 2019 related to Transition Obligations	92,005
Estimated Future Employer Contributions in 2019	8,063,471
Other postretirement benefit plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Net Periodic Pension Cost	887,000	$ 1,006,000	$ 1,142,000
Projected Benefit Payments for 2019	1,600,000
Projected Benefit Payments for 2020	1,500,000
Projected Benefit Payments for 2021	1,400,000
Projected Benefit Payments for 2022	1,400,000
Projected Benefit Payments for 2023	1,300,000
Projected Benefit Payments for 2024 through 2028	5,400,000
Accumulated Other Comprehensive Loss Expected to be Recognized in Net Periodic Pension Cost during 2019 related to Net Actuarial Losses	248,457
Accumulated Other Comprehensive Income Expected to be Recognized in Net Periodic Pension Cost during 2019 related to Prior Service Credit	(90,321)
Estimated Future Employer Contributions in 2019	$ 1,630,981