Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock	Treasury Stock	Additional Paid in Capital	Retained Earnings	Accumulated Other Comprehensive (Loss)
Beginning Balance at Mar. 31, 2019	$ 936,890	$ 451	$ (138,852)	$ 690,507	$ 399,473	$ (14,689)
Beginning Balance (in shares) at Mar. 31, 2019		45,122,985	1,903,241
Restricted stock units issued		$ 4		(4)
Restricted stock units issued (in shares)		392,872
Stock options exercised	3,748	$ 2		3,747
Stock options exercised (in shares)		85,136
Stock issued under employee stock purchase plan	5,103			5,103
Stock issued under employee stock purchase plan (in shares)		37,827
Return of common stock to pay withholding taxes on restricted stock	(41,687)	$ (2)	$ (41,685)
Return of common stock to pay withholding taxes on restricted stock (in shares)		(164,446)	164,446
Stock - based compensation expense	39,781			39,781
Stock repurchase program	$ (84,879)	$ (5)	$ (84,874)
Stock repurchase program, (in shares)	(465,687)	(465,687)	465,687
Other comprehensive income (loss)	$ 3,500					3,500
Net income	203,009				203,009
Ending Balance at Mar. 31, 2020	1,065,466	$ 451	$ (265,411)	739,133	602,482	(11,189)
Ending Balance (in shares) at Mar. 31, 2020		45,008,687	2,533,374
Restricted stock units issued	1	$ 2		(1)
Restricted stock units issued (in shares)		140,159
Stock options exercised	9,075	$ 2		9,073
Stock options exercised (in shares)		215,262
Stock issued under employee stock purchase plan	5,479			5,479
Stock issued under employee stock purchase plan (in shares)		31,920
Return of common stock to pay withholding taxes on restricted stock	(11,311)	$ (1)	$ (11,310)
Return of common stock to pay withholding taxes on restricted stock (in shares)		57,431	(57,431)
Stock - based compensation expense	47,006			47,006
Stock repurchase program	$ (11,310)	$ (1)	$ (11,309)
Stock repurchase program, (in shares)	(67,649)	(67,649)	67,649
Other comprehensive income (loss)	$ (256)					(256)
Net income	225,525				225,525
Ending Balance at Mar. 31, 2021	$ 1,329,675	$ 453	$ (288,030)	800,690	828,007	(11,445)
Ending Balance (in shares) at Mar. 31, 2021	45,271,000	45,270,948	2,658,454
Restricted stock units issued		$ 1		(1)
Restricted stock units issued (in shares)		134,288
Stock options exercised	$ 9,424	$ 2		9,422
Stock options exercised (in shares)	168,000	168,279
Stock issued under employee stock purchase plan	$ 7,234			7,234
Stock issued under employee stock purchase plan (in shares)		26,594
Return of common stock to pay withholding taxes on restricted stock	(16,526)	$ 1	$ 16,525
Return of common stock to pay withholding taxes on restricted stock (in shares)		(54,671)	54,671
Stock - based compensation expense	52,729			52,729
Other comprehensive income (loss)	(15,715)					(15,715)
Net income	136,505				136,505
Ending Balance at Mar. 31, 2022	$ 1,503,326	$ 455	$ (304,555)	$ 870,074	$ 964,512	$ (27,160)
Ending Balance (in shares) at Mar. 31, 2022	45,545,000	45,545,438	2,713,125