Accounts and Taxes Payable and Accrued Liabilities - Accrued Liabilities (Detail) - USD ($)	Sep. 30, 2017	Mar. 31, 2017
Payables And Accruals [Abstract]
Payroll, payroll taxes and employee benefits	$ 18,468,000	$ 14,465,000
Customer deposits	39,038,000	32,471,000
Accrued professional service fees	4,567,000	4,551,000
Self-insurance accruals	3,195,000	2,835,000
Deferred revenue	12,503,000	10,096,000
Accrued rent	5,355,000	5,774,000
Other	3,137,000	3,276,000
Total accrued liabilities	$ 86,263,000	$ 73,468,000