Contract Balances and Contract Costs - Disaggregation of Revenue by Service Type (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 31, 2020	Aug. 02, 2019	Jul. 31, 2020	Aug. 02, 2019
Disaggregation of Revenue [Line Items]
Net revenue	$ 138,476	$ 136,605	$ 279,657	$ 269,447
Managed Security Solutions revenue
Disaggregation of Revenue [Line Items]
Net revenue	106,259	102,768	212,616	201,866
Security and Risk Consulting revenue
Disaggregation of Revenue [Line Items]
Net revenue	$ 32,217	$ 33,837	$ 67,041	$ 67,581