Pension and Other Post-retirement Benefit Plans (Details 1) (USD $) In Thousands, unless otherwise specified	6 Months Ended	12 Months Ended
	Mar. 31, 2013	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012
Pension
Amounts recognized in the Consolidated Balance Sheets
Current liability	$ (644)	$ (615)	$ (644)
Noncurrent liability	(29,646)	(32,154)	(29,646)
Amount recognized, end of year	(30,290)	(32,769)	(30,290)
Accumulated other comprehensive income (loss)
Net actuarial loss (gain)	9,742	9,269	9,742
Prior service cost	32	310	32
Accumulated other comprehensive income	9,774	9,579	9,774
Components of benefit costs (credit)
Net service cost		1,308	1,583	1,310
Interest cost		1,734	1,903	2,111
Expected return on plan assets		(454)	(656)	(712)
Amortization:
Actuarial (gain) loss		318	544	392
Prior service cost		4	20	25
Recurring activity		2,910	3,394	3,126
Curtailment expense	2,000	(32)	266	0
Net periodic benefit cost (credit)		2,878	3,660	3,126
Other Benefits
Amounts recognized in the Consolidated Balance Sheets
Current liability	(90)	(88)	(90)
Noncurrent liability	(709)	(697)	(709)
Amount recognized, end of year	(799)	(785)	(799)
Accumulated other comprehensive income (loss)
Net actuarial loss (gain)	(1,818)	(1,464)	(1,818)
Prior service cost	0	0	0
Accumulated other comprehensive income	(1,818)	(1,464)	(1,818)
Components of benefit costs (credit)
Net service cost		0	0	0
Interest cost		23	27	44
Expected return on plan assets		0	0	0
Amortization:
Actuarial (gain) loss		(259)	(322)	(323)
Prior service cost		0	0	0
Recurring activity		(236)	(295)	(279)
Curtailment expense		0	0	0
Net periodic benefit cost (credit)		$ (236)	$ (295)	$ (279)