Revenue Changes in Contract Assets and Liabilities (Details) - USD ($) $ in Thousands	12 Months Ended
	Jan. 31, 2019	Jan. 31, 2018
Capitalized Contract Cost [Line Items]
Performance obligations more than one year	$ 0	$ 0
Short-term Contract with Customer [Member]
Capitalized Contract Cost [Line Items]
Contract assets	2,027	3,119
Contract asset $ change	$ (1,092)
Contract asset % change	(35.00%)
Contract liabilities	$ 1,303	$ 1,890
Contract liability $ change	$ (587)
Contract liability % change	(31.10%)