Benefit Plans (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2016	Dec. 31, 2015
Pension Benefits [Member]
Components of net periodic cost:
Service cost	$ 32	$ 23	$ 63	$ 46
Interest cost	173	216	346	432
Expected return on plan assets	(115)	(123)	(230)	(246)
Recognized net actuarial loss (gain)	218	229	436	457
Amortization of prior service cost	21	21	43	43
Net periodic cost	329	366	658	732
Retiree Health Care Benefits [Member]
Components of net periodic cost:
Service cost	7	6	14	12
Interest cost	16	19	32	38
Expected return on plan assets	0	0	0	0
Recognized net actuarial loss (gain)	(46)	(53)	(91)	(106)
Amortization of prior service cost	(67)	(68)	(135)	(136)
Net periodic cost	$ (90)	$ (96)	$ (180)	$ (192)