CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Oct. 31, 2013	Oct. 31, 2012
Cash flows from operating activities:
Net income	$ 2,986	$ 13,636
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	23,242	26,270
Stock-based compensation	839	1,323
Provision for doubtful accounts, net of charge offs	1,048	(443)
Provision for inventory obsolescence	70	178
Gross profit from sale of lease pool equipment	(4,108)	(3,657)
Excess tax benefit from exercise of non-qualified stock options and restricted shares	(44)	(441)
Deferred tax provision	(2,495)	(3,524)
Changes in non-current income taxes payable		(5,003)
Changes in working capital items:
Accounts receivable	(4,569)	17,662
Contracts and notes receivable	1,277	(761)
Inventories	(2,827)	(623)
Prepaid expenses and other current assets	(1,449)	(1,341)
Income taxes payable	3,382	(7,672)
Prepaid foreign income tax		3,519
Accounts payable, accrued expenses, other current liabilities and deferred revenue	1,338	(2,801)
Net cash provided by operating activities	18,690	36,129
Cash flows from investing activities:
Purchases of seismic equipment held for lease	(13,308)	(35,531)
Purchases of property and equipment	(452)	(795)
Sale of used lease pool equipment	6,188	7,409
Net cash used in investing activities	(7,572)	(28,917)
Cash flows from financing activities:
Net payments on revolving line of credit	(1,000)	650
Proceeds from equipment notes		180
Payments on borrowings	(105)	(1,528)
Net purchases of short-term investments	30
Proceeds from issuance of common stock upon exercise of options	275	331
Purchase of treasury stock	(2,200)
Excess tax benefit from exercise of non-qualified stock options and restricted shares	44	441
Net cash (used in) provided by financing activities	(2,956)	74
Effect of changes in foreign exchange rates on cash and cash equivalents	897	1,417
Net change in cash and cash equivalents	9,059	8,703
Cash and cash equivalents, beginning of period	15,150	15,287
Cash and cash equivalents, end of period	24,209	23,990
Supplemental cash flow information:
Interest paid	206	447
Income taxes (refunded) paid	(74)	8,222
Purchases of seismic equipment held for lease in accounts payable at end of period	$ 5,208	$ 835