Benefit Plans (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2012	Dec. 31, 2011
Components of net periodic cost:
Curtailment loss		$ (3,117)		$ (3,117)
Pension Benefits [Member]
Components of net periodic cost:
Service cost	20	127	39	254
Interest cost	315	588	630	1,176
Expected return on plan assets	(101)	(99)	(202)	(198)
Recognized net actuarial loss (gain)	184	265	368	529
Amortization of prior service cost	21	185	42	370
Curtailment loss		3,117		3,117
Net periodic cost	439	4,183	877	5,248
Retiree Health Care Benefits [Member]
Components of net periodic cost:
Service cost	20	8	40	15
Interest cost	47	59	94	118
Expected return on plan assets
Recognized net actuarial loss (gain)	(14)	(18)	(27)	(36)
Amortization of prior service cost	27	35	54	70
Curtailment loss
Net periodic cost	$ 80	$ 84	$ 161	$ 167