Consolidated Statements of Stockholders' Equity (USD $)	Total	Common Stock	Paid-in-Capital	Treasury Shares	Retained Earnings
Beginning balance at Mar. 31, 2009	$ 96,297,000	$ 3,000	$ 84,321,000	$ (185,762,000)	$ 197,735,000
Beginning balance, shares at Mar. 31, 2009		25,600,022		(12,682,743)
Stock issued under employee stock purchase plan, shares		11,064
Stock issued under employee stock purchase plan	333,000		333,000
Stock issued under stock option plan, net of shares repurchased, shares		190,604
Stock issued under stock option plan, net of shares repurchased	2,732,000		2,732,000
Stock-based compensation expense	2,102,000		2,102,000
Income tax benefits from stock option exercises	729,000		729,000
Purchase of treasury stock, shares				(1,092,445)
Purchase of treasury stock	(32,561,000)			(32,561,000)
Net income	26,096,000				26,096,000
Ending balance at Mar. 31, 2010	95,728,000	3,000	90,217,000	(218,323,000)	223,831,000
Ending balance, shares at Mar. 31, 2010		25,801,690		(13,775,188)
Stock issued under employee stock purchase plan, shares		7,073
Stock issued under employee stock purchase plan	317,000		317,000
Stock issued under stock option plan, net of shares repurchased, shares		313,321
Stock issued under stock option plan, net of shares repurchased	4,728,000		4,728,000
Stock-based compensation expense	2,544,000		2,544,000
Income tax benefits from stock option exercises	2,267,000		2,267,000
Purchase of treasury stock, shares				(715,975)
Purchase of treasury stock	(30,608,000)			(30,608,000)
Net income	24,663,000				24,663,000
Ending balance at Mar. 31, 2011	99,639,000	3,000	100,073,000	(248,931,000)	248,494,000
Ending balance, shares at Mar. 31, 2011		26,122,084		(14,491,163)
Stock issued under employee stock purchase plan, shares		8,215
Stock issued under employee stock purchase plan	321,000		321,000
Stock issued under stock option plan, net of shares repurchased, shares		131,575
Stock issued under stock option plan, net of shares repurchased	2,241,000		2,241,000
Stock-based compensation expense	2,276,000		2,276,000
Income tax benefits from stock option exercises	996,000		996,000
Purchase of treasury stock, shares				(461,938)
Purchase of treasury stock	(21,643,000)			(21,643,000)
Net income	26,552,000				26,552,000
Ending balance at Mar. 31, 2012	$ 110,382,000	$ 3,000	$ 105,907,000	$ (270,574,000)	$ 275,046,000
Ending balance, shares at Mar. 31, 2012		26,261,874		(14,953,101)