Benefit Plans (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2013	Mar. 31, 2012
Components of net periodic cost:
Curtailment loss				$ (3,117)
Pension Benefits [Member]
Components of net periodic cost:
Service cost	20	17	60	271
Interest cost	314	436	945	1,612
Expected return on plan assets	(101)	(99)	(303)	(297)
Recognized net actuarial loss (gain)	184	57	551	586
Amortization of prior service cost	21	21	62	391
Curtailment loss				3,117
Net periodic cost	438	432	1,315	5,680
Retiree Health Care Benefits [Member]
Components of net periodic cost:
Service cost	20	7	60	22
Interest cost	47	59	142	177
Expected return on plan assets
Recognized net actuarial loss (gain)	(13)	(18)	(40)	(54)
Amortization of prior service cost	27	35	80	105
Curtailment loss
Net periodic cost	$ 81	$ 83	$ 242	$ 250