Schedule II - Valuation and Qualifying Accounts (Detail) - Allowance for Doubtful Accounts [Member] - USD ($)	12 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2020
Valuation And Qualifying Accounts Disclosure [Line Items]
Balance at Beginning of Year	$ 3,274,000	$ 5,133,000	$ 5,508,000
Additions Charged to Cost and Expenses	158,000	2,021,000	1,606,000
Deductions	(870,000)	(3,880,000)	(1,981,000)
Balance at End of Year	$ 2,562,000	$ 3,274,000	$ 5,133,000