Schedule II - Valuation and Qualifying Accounts (Detail) - USD ($) $ in Thousands	12 Months Ended
	Jan. 31, 2019	Jan. 31, 2018	Jan. 31, 2017
Allowance for doubtful accounts
Allowance for Doubtful Accounts and Allowance for Obsolete Equipment and Inventory [Roll Forward]
Balance at Beginning of Period	$ 6,167	$ 5,904	$ 5,821
Charged to Costs and Expenses	212	1,027	737
Charged to Other Accounts	0	(23)	(31)
Deductions Describe	(4,266)	(741)	(623)
Balance at End of Period	2,113	6,167	5,904
Allowance for obsolete equipment and inventory
Allowance for Doubtful Accounts and Allowance for Obsolete Equipment and Inventory [Roll Forward]
Balance at Beginning of Period	1,675	952	900
Charged to Costs and Expenses	132	989	116
Charged to Other Accounts	(32)	20	(41)
Deductions Describe	(553)	(286)	(23)
Balance at End of Period	$ 1,222	$ 1,675	$ 952