Schedule of Accrued Expenses (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Mar. 31, 2017
Accounts Payable And Accrued Liabilities Current [Abstract]
Payroll and Incentive Compensation	$ 25,290	$ 22,850
Benefits	13,785	11,503
Interest	3,852	5,992
Property Taxes	5,422	4,759
Power and Fuel	1,545	1,536
Litigation Settlements	45,098
Legal	1,435	2,459
Sales and Use Tax	890	944
Acquisition Related Expenses		350
Other	8,553	4,986
Accrued expenses, total	$ 105,870	$ 55,379