Pension Plans and Other Postretirement Benefit Plan (Schedule of Net Periodic Benefit Cost) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2019	Dec. 31, 2018
Pension Plans [Member]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost	$ 121	$ 111	$ 242	$ 222
Interest cost	354	402	708	804
Expected return on plan assets	(244)	(144)	(488)	(288)
Recognized actuarial loss (a)	134	119	268	238
Amortization of unrecognized prior service credit (a)	0	0	0	0
Settlement gain (a)			0	(8)
Net periodic benefit cost	365	488	730	968
Postretirement Plan [Member]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost	13	18	26	36
Interest cost	15	38	30	76
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)	(2)	(4)
Settlement gain (a)			0	0
Net periodic benefit cost	$ 27	$ 54	$ 54	$ 108