Assets Held for Sale - Additional Details Related to the Assets and Liabilities for SAP (Details) - USD ($) $ in Thousands	Jan. 31, 2019	Jan. 31, 2018
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Total current assets held for sale	$ 2,202	$ 0
Long-term assets held for sale	286	0
Current liabilities held for sale	892	$ 0
SAP | Discontinued Operations, Held-for-sale or Disposed of by Sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Cash and cash equivalents	458
Accounts receivable, net	1,256
Inventories, net	420
Prepaid expenses and other current assets	68
Total current assets held for sale	2,202
Seismic equipment lease pool and property and equipment, net	259
Other assets	27
Long-term assets held for sale	286
Accounts payable	479
Accrued expenses and other current liabilities	413
Current liabilities held for sale	$ 892