Employee Benefit Plans (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2012	Dec. 31, 2011
Defined Benefit Pension Plans and Defined Benefit Postretirement Plans Disclosure [Abstract]
Service cost for benefits earned during the period	$ 155	$ 129	$ 466	$ 386
Interest cost on accumulated postretirement benefit	139	142	416	426
Other components	1	(4)	3	(12)
Net periodic postretirement benefit cost	$ 295	$ 267	$ 885	$ 800