Defined Benefit Pension Plan - Percentage of fair value (Details)	12 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Defined Benefit Plan Disclosure [Line Items]
Change in Fair Value of Plan Asset, Percentage	100.00%	100.00%
Cash Equivalents
Defined Benefit Plan Disclosure [Line Items]
Change in Fair Value of Plan Asset, Percentage	0.90%	5.60%
Equities - Large Cap
Defined Benefit Plan Disclosure [Line Items]
Change in Fair Value of Plan Asset, Percentage	48.60%	43.00%
Equities - Mid Cap
Defined Benefit Plan Disclosure [Line Items]
Change in Fair Value of Plan Asset, Percentage	4.30%	3.40%
Equities - Small Cap
Defined Benefit Plan Disclosure [Line Items]
Change in Fair Value of Plan Asset, Percentage	25.30%	33.70%
Equities - International
Defined Benefit Plan Disclosure [Line Items]
Change in Fair Value of Plan Asset, Percentage	4.00%	2.10%
Equities - Other
Defined Benefit Plan Disclosure [Line Items]
Change in Fair Value of Plan Asset, Percentage	8.30%	8.50%
Alternatives/Multi-Asset
Defined Benefit Plan Disclosure [Line Items]
Change in Fair Value of Plan Asset, Percentage	8.60%	3.70%