Segment Reporting (Details 1) (USD $) In Thousands, unless otherwise specified	3 Months Ended
Apr. 30, 2013	Apr. 30, 2012
Financial information by business segment
Revenues	$ 27,291	$ 34,631
Operating income	8,183	11,666
Income before taxes	7,919	11,063
Equipment Leasing [Member]
Financial information by business segment
Revenues	23,364	24,087
Operating income	8,158	7,027
Income before taxes	7,835	6,726
Seamap [Member]
Financial information by business segment
Revenues	3,934	10,841
Operating income	(26)	4,561
Income before taxes	33	4,259
Eliminations [Member]
Financial information by business segment
Revenues	(7)	(297)
Operating income	51	78
Income before taxes	$ 51	$ 78

Sum of operating profit and nonoperating income or expense before Income or Loss from equity method investments, income taxes, extraordinary items, and noncontrolling interest.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 235

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.4-08.(h)(1)(i))

-URI http://asc.fasb.org/extlink&oid=6881521&loc=d3e23780-122690

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 08

-Paragraph h

-Subparagraph 1(i)

-Article 4

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- Definition

The net result for the period of deducting operating expenses from operating revenues.

+ References

No definition available.

+ Details

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- Definition

Aggregate revenue recognized during the period (derived from goods sold, services rendered, insurance premiums, or other activities that constitute an entity's earning process). For financial services companies, also includes investment and interest income, and sales and trading gains.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 225

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SX 210.5-03.1)

-URI http://asc.fasb.org/extlink&oid=6880815&loc=d3e20235-122688

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 1

-Article 5

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