Statement of Comprehensive Income (Parentheticals) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2011
Statement of Income and Comprehensive Income [Abstract]
Other comprehensive income (loss), unrealized holding gain (loss) on securities arising during period, tax	$ 68	$ (30)	$ (22)
Other comprehensive income (loss), pension and other postretirement benefit plans, net unamortized gain (loss) arising during period, tax	$ 418	$ 415	$ 577