Income Taxes (Details 3) (USD $)	12 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2011
Income Taxes
Unrecognized tax benefits that, if recognized, would affect effective tax rate	$ 115,000	$ 1,300,000
Accrued payment of potential interest and penalties	68,000	56,000
Gross unrecognized tax benefits
Balance at the beginning of the year	1,692,000	1,941,000	2,153,000
Increases for tax positions taken in prior years		97,000	121,000
Decreases for tax positions taken in prior years	(1,431,000)	(10,000)	(15,000)
Increases for tax positions taken in the current year	17,000	20,000	17,000
Settlement with taxing authorities			(8,000)
Lapse in statute of limitations	(60,000)	(356,000)	(327,000)
Balance at the end of the year	218,000	1,692,000	1,941,000
Estimated tax credit carryforwards		1,400,000
Decrease in gross unrecognized tax benefits within next twelve months	$ 30,000