Pension Plans and Other Postretirement Benefit Plan (Schedule of Net Periodic Benefit Cost) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Mar. 31, 2020	Mar. 31, 2019
Pension Plans [Member]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost	$ 121	$ 111	$ 363	$ 333
Interest cost	354	402	1,062	1,206
Expected return on plan assets	(244)	(144)	(732)	(432)
Recognized actuarial loss (a)	134	119	402	357
Amortization of unrecognized prior service credit (a)	0	0	0	0
Settlement gain (a)			0	(8)
Net periodic benefit cost	365	488	1,095	1,456
Postretirement Plan [Member]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost	13	18	39	54
Interest cost	15	38	45	114
Expected return on plan assets	0	0	0	0
Recognized actuarial loss (a)	0	0	0	0
Amortization of unrecognized prior service credit (a)	(1)	(2)	(3)	(6)
Settlement gain (a)			0	0
Net periodic benefit cost	$ 27	$ 54	$ 81	$ 162