Defined Benefit Pension Plan - Percentage of fair value (Details)	12 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
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	5.60%	0.90%
Equities - Large Cap
Defined Benefit Plan Disclosure [Line Items]
Change in Fair Value of Plan Asset, Percentage	43.00%	59.90%
Equities - Mid Cap
Defined Benefit Plan Disclosure [Line Items]
Change in Fair Value of Plan Asset, Percentage	3.40%	3.40%
Equities - Small Cap
Defined Benefit Plan Disclosure [Line Items]
Change in Fair Value of Plan Asset, Percentage	33.70%	31.30%
Equities - International
Defined Benefit Plan Disclosure [Line Items]
Change in Fair Value of Plan Asset, Percentage	2.10%	2.50%
Equities - Other
Defined Benefit Plan Disclosure [Line Items]
Change in Fair Value of Plan Asset, Percentage	8.50%
Alternatives/Multi-Asset
Defined Benefit Plan Disclosure [Line Items]
Change in Fair Value of Plan Asset, Percentage	3.70%
Certificates of deposit
Defined Benefit Plan Disclosure [Line Items]
Change in Fair Value of Plan Asset, Percentage		2.00%