Accounts and Income Taxes Payable and Accrued Liabilities - Accrued Liabilities (Detail) - USD ($)	Sep. 30, 2024	Mar. 31, 2024
Payables and Accruals [Abstract]
Payroll, payroll taxes and employee benefits	$ 36,533,000	$ 26,291,000
Customer deposits	109,110,000	88,142,000
Accrued professional service fees	9,617,000	9,838,000
Self-insurance accruals	3,488,000	3,818,000
Deferred revenue	29,958,000	29,961,000
Operating lease liabilities	8,779,000	8,864,000
Other	1,200,000	954,000
Total accrued liabilities	$ 198,685,000	$ 167,868,000