Income Taxes - Summary of Reconciliation Income Tax Provision from the Statutory Federal Income Tax Rate (Detail) - USD ($)	12 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Mar. 31, 2022
Income Tax Disclosure [Abstract]
Income taxes at federal statutory rate	$ 19,971,000	$ 17,757,000	$ 17,748,000
State income taxes, net of federal benefit	3,369,000	3,890,000	3,658,000
Uncertain tax positions	(22,000)	(77,000)	(222,000)
Stock-based compensation and 162(m) limitation	(3,961,000)	(3,098,000)	(2,697,000)
Permanent items and tax credits	(480,000)	(384,000)	(465,000)
Adjustments to returns as filed	67,000	163,000	176,000
Valuation allowance	(95,000)	(62,000)	(96,000)
Total	$ 18,849,000	$ 18,189,000	$ 18,102,000