Valuation and Qualifying Accounts (Parenthetical) (Details) - USD ($) $ in Thousands	12 Months Ended
	Jan. 31, 2018	Jan. 31, 2017	Jan. 31, 2016
Valuation And Qualifying Accounts [Abstract]
Prior year adjustments		$ 89	$ 177
Expiration/Expired of tax losses	$ (479)		(745)
Reversal due to legal entity elimination		(280)
Adjustments	$ (479)	$ (191)	$ (568)