Benefit Plans - Components of Net Periodic Other Postretirement Benefit Cost (Details) - Other postretirement benefit plans [Member] - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Mar. 31, 2016	Mar. 31, 2015
Net periodic other postretirement benefit costs
Service cost	$ 0	$ 27	$ 0	$ 81
Interest cost	210	259	630	778
Amortization of prior service credit	(6)	(28)	(16)	(83)
Recognition of actuarial loss (gains)	81	207	242	621
Curtailment Gain	0	0	0	(221)
Net periodic other postretirement benefit cost	$ 285	$ 465	$ 856	$ 1,176