Benefit Plans (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Mar. 31, 2016	Mar. 31, 2015
Pension Benefits [Member]
Components of net periodic cost:
Service cost	$ 23	$ 24	$ 69	$ 73
Interest cost	216	224	648	672
Expected return on plan assets	(122)	(124)	(368)	(371)
Recognized net actuarial loss (gain)	228	140	685	419
Amortization of prior service cost	21	21	64	64
Net periodic cost	366	285	1,098	857
Retiree Health Care Benefits [Member]
Components of net periodic cost:
Service cost	5	13	17	39
Interest cost	18	24	56	71
Expected return on plan assets	0	0	0	0
Recognized net actuarial loss (gain)	(52)	(22)	(158)	(66)
Amortization of prior service cost	(67)	(68)	(203)	(203)
Net periodic cost	$ (96)	$ (53)	$ (288)	$ (159)