- Employee Retirement Benefits (Details) $ in Thousands	12 Months Ended
	Jan. 31, 2019 USD ($) contribution_plan	Jan. 31, 2018 USD ($)	Jan. 31, 2017 USD ($)
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Number of defined contribution plans | contribution_plan	1
Defined contribution current payroll matching percentage	5.00%	5.00%	4.00%
Participant contribution rate for company stock, maximum	10.00%
Total contribution expense | $	$ 3,006	$ 2,263	$ 2,030
Maximum
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Percentage of Participant balance transferred into Raven common stock	10.00%
Percentage of participant balance allowed in Raven Common stock	10.00%