CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - UNAUDITED - USD ($)	Total	Common Stock [Member]	Paid-in Capital [Member]	Treasury Stock [Member]	Retained Earnings [Member]
Beginning balance at Mar. 31, 2021	$ 220,402,000	$ 3,000	$ 185,941,000	$ (564,435,000)	$ 598,893,000
Beginning balance, shares at Mar. 31, 2021		54,529,642		(36,653,552)
Stock issued under employee stock purchase plan	271,000		271,000
Stock issued under employee stock purchase plan, shares		1,534
Stock issued under stock option plan, net of shares repurchased	7,261,000		7,261,000
Stock issued under stock option plan, net of shares repurchased, shares		170,300
Stock-based compensation expense	2,701,000		2,701,000
Purchase of treasury stock	(39,755,000)			$ (39,755,000)
Purchase of treasury stock, shares				(284,348)
Net income	32,915,000				32,915,000
Ending balance at Sep. 30, 2021	223,795,000	$ 3,000	196,174,000	$ (604,190,000)	631,808,000
Ending balance, shares at Sep. 30, 2021		54,701,476		(36,937,900)
Beginning balance at Jun. 30, 2021	229,539,000	$ 3,000	192,431,000	$ (578,631,000)	615,736,000
Beginning balance, shares at Jun. 30, 2021		54,642,752		(36,772,445)
Stock issued under employee stock purchase plan	271,000		271,000
Stock issued under employee stock purchase plan, shares		1,534
Stock issued under stock option plan, net of shares repurchased	2,117,000		2,117,000
Stock issued under stock option plan, net of shares repurchased, shares		57,190
Stock-based compensation expense	1,355,000		1,355,000
Purchase of treasury stock	(25,559,000)			$ (25,559,000)
Purchase of treasury stock, shares				(165,455)
Net income	16,072,000				16,072,000
Ending balance at Sep. 30, 2021	223,795,000	$ 3,000	196,174,000	$ (604,190,000)	631,808,000
Ending balance, shares at Sep. 30, 2021		54,701,476		(36,937,900)
Beginning balance at Mar. 31, 2022	212,395,000	$ 3,000	201,609,000	$ (654,520,000)	665,303,000
Beginning balance, shares at Mar. 31, 2022		54,788,712		(37,219,625)
Stock issued under employee stock purchase plan	346,000		346,000
Stock issued under employee stock purchase plan, shares		2,636
Stock issued under stock option plan, net of shares repurchased	3,702,000		3,702,000
Stock issued under stock option plan, net of shares repurchased, shares		81,854
Stock-based compensation expense	2,329,000		2,329,000
Purchase of treasury stock	$ (52,286,000)			$ (52,286,000)
Purchase of treasury stock, shares	(339,391)			(339,391)
Net income	$ 31,347,000				31,347,000
Ending balance at Sep. 30, 2022	197,833,000	$ 3,000	207,986,000	$ (706,806,000)	696,650,000
Ending balance, shares at Sep. 30, 2022		54,873,202		(37,559,016)
Beginning balance at Jun. 30, 2022	205,628,000	$ 3,000	204,839,000	$ (681,208,000)	681,994,000
Beginning balance, shares at Jun. 30, 2022		54,832,358		(37,394,507)
Stock issued under employee stock purchase plan	346,000		346,000
Stock issued under employee stock purchase plan, shares		2,636
Stock issued under stock option plan, net of shares repurchased	1,851,000		1,851,000
Stock issued under stock option plan, net of shares repurchased, shares		38,208
Stock-based compensation expense	950,000		950,000
Purchase of treasury stock	$ (25,598,000)			$ 25,598,000
Purchase of treasury stock, shares	(164,509)			(164,509)
Net income	$ 14,656,000				14,656,000
Ending balance at Sep. 30, 2022	$ 197,833,000	$ 3,000	$ 207,986,000	$ (706,806,000)	$ 696,650,000
Ending balance, shares at Sep. 30, 2022		54,873,202		(37,559,016)