Schedule of Accrued Expenses (Detail) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Accounts Payable And Accrued Liabilities Current [Abstract]
Payroll and Incentive Compensation	$ 19,082	$ 12,855
Benefits	9,951	10,158
Interest	4,524	4,813
Property Taxes	3,189	2,801
Power and Fuel	1,619	2,132
Legal	1,673	1,831
Sales and Use Tax	523	658
Acquisition Related Expenses	1,355
Other	4,914	6,272
Accrued expenses, total	$ 46,830	$ 41,520