Accounts and Income Taxes Payable and Accrued Liabilities - Accrued Liabilities (Detail) - USD ($)	Mar. 31, 2020	Mar. 31, 2019
Payables And Accruals [Abstract]
Payroll, payroll taxes and employee benefits	$ 26,024,000	$ 23,647,000
Customer deposits	48,991,000	45,268,000
Accrued professional service fees	5,919,000	8,377,000
Self-insurance accruals	3,248,000	3,523,000
Deferred revenue	17,645,000	16,900,000
Operating lease liabilities	13,223,000	5,708,000
Other	2,276,000	2,018,000
Total accrued liabilities	$ 117,326,000	$ 105,441,000