Income Taxes - Summary of Reconciliation Income Tax Provision from the Statutory Federal Income Tax Rate (Detail) - USD ($)	12 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2020
Income Tax Disclosure [Abstract]
Income taxes at federal statutory rate	$ 17,748,000	$ 12,427,000	$ 12,749,000
State income taxes, net of federal benefit	3,658,000	3,102,000	2,243,000
Uncertain tax positions	(222,000)	(693,000)	(263,000)
Stock-based compensation and 162(m) limitation	(2,697,000)	(1,654,000)	(1,453,000)
Permanent items and tax credits	(465,000)	(364,000)	(179,000)
Adjustments to returns as filed	176,000	192,000	110,000
Valuation allowance	(96,000)	(191,000)	(127,000)
Total	$ 18,102,000	$ 12,819,000	$ 13,334,000