Consolidated Statements of Stockholders' Equity (USD $)	Total	Common Stock [Member]	Paid-in Capital [Member]	Treasury Stock [Member]	Retained Earnings [Member]
Beginning balance at Mar. 31, 2012	$ 110,382,000	$ 3,000	$ 105,907,000	$ (270,574,000)	$ 275,046,000
Beginning balance, shares at Mar. 31, 2012		52,523,748		(29,906,202)
Stock issued under employee stock purchase plan	313,000		313,000
Stock issued under employee stock purchase plan, shares		14,056
Stock issued under stock option plan, net of shares repurchased	3,399,000		3,399,000
Stock issued under stock option plan, net of shares repurchased, shares		299,458
Stock-based compensation expense	997,000		997,000
Income tax benefits from stock option exercises	308,000		308,000
Purchase of treasury stock	(30,727,000)			(30,727,000)
Purchase of treasury stock, shares	(1,410,812)			(1,410,812)
Net Income	26,730,000				26,730,000
Ending balance at Mar. 31, 2013	111,402,000	3,000	110,924,000	(301,301,000)	301,776,000
Ending balance, shares at Mar. 31, 2013		52,837,262		(31,317,014)
Stock issued under employee stock purchase plan	346,000		346,000
Stock issued under employee stock purchase plan, shares		8,489
Stock issued under stock option plan, net of shares repurchased	3,386,000		3,386,000
Stock issued under stock option plan, net of shares repurchased, shares		281,115
Stock-based compensation expense	2,140,000		2,140,000
Income tax benefits from stock option exercises	2,035,000		2,035,000
Purchase of treasury stock	(27,179,000)			(27,179,000)
Purchase of treasury stock, shares	(830,460)			(830,460)
Net Income	34,392,000				34,392,000
Ending balance at Mar. 31, 2014	126,522,000	3,000	118,831,000	(328,480,000)	336,168,000
Ending balance, shares at Mar. 31, 2014		53,126,866		(32,147,474)
Stock issued under employee stock purchase plan	400,000		400,000
Stock issued under employee stock purchase plan, shares	2,439,296	12,299
Stock issued under stock option plan, net of shares repurchased	1,603,000		1,603,000
Stock issued under stock option plan, net of shares repurchased, shares		103,992
Stock-based compensation expense	2,209,000		2,209,000
Income tax benefits from stock option exercises	397,000		397,000
Purchase of treasury stock	(31,798,000)			(31,798,000)
Purchase of treasury stock, shares	(845,014)			(845,014)
Net Income	28,590,000				28,590,000
Ending balance at Mar. 31, 2015	$ 127,923,000	$ 3,000	$ 123,440,000	$ (360,278,000)	$ 364,758,000
Ending balance, shares at Mar. 31, 2015		53,243,157		(32,992,488)