Schedule II - Valuation and Qualifying Accounts (Detail) - USD ($) $ in Thousands	12 Months Ended
	Jan. 31, 2018	Jan. 31, 2017	Jan. 31, 2016
Allowance for doubtful accounts
Allowance for Doubtful Accounts and Allowance for Obsolete Equipment and Inventory [Roll Forward]
Balance at Beginning of Period	$ 5,904	$ 5,821	$ 6,339
Charged to Costs and Expenses	1,027	737	2,069
Charged to Other Accounts	(23)	(31)	404
Deductions Describe	(741)	(623)	(2,991)
Balance at End of Period	6,167	5,904	5,821
Allowance for obsolete equipment and inventory
Allowance for Doubtful Accounts and Allowance for Obsolete Equipment and Inventory [Roll Forward]
Balance at Beginning of Period	952	900	750
Charged to Costs and Expenses	989	116	208
Charged to Other Accounts	20	(41)	(58)
Deductions Describe	(286)	(23)	0
Balance at End of Period	$ 1,675	$ 952	$ 900