Consolidated Statements of Comprehensive Income (Parenthetical) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2012	Dec. 31, 2011
Other comprehensive income (loss):
Unrealized holding gains (losses), tax provision (benefit)	$ (30)	$ (2)	$ 14	$ 167