Leases - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Jan. 31, 2020	Jan. 31, 2019	Jan. 31, 2018	Apr. 30, 2019	Feb. 01, 2019
Lessee, Lease, Description [Line Items]
Operating lease right-of-use assets	$ 2,300			$ 3,000	$ 2,710
Total operating lease liabilities	2,300			$ 3,000	$ 2,710
Lease expense	1,200
Short-term lease expense	30
Seismic equipment lease pool
Lessee, Lease, Description [Line Items]
Lease expense incurred by the Company	2,500	$ 1,900	$ 774
Office
Lessee, Lease, Description [Line Items]
Lease expense incurred by the Company	$ 1,200	$ 1,300	$ 1,200
Maximum
Lessee, Lease, Description [Line Items]
Operating leases, non-cancelable term (in years)	1 year