Segment Reporting (Details) (USD $)	3 Months Ended
	Apr. 30, 2013	Apr. 30, 2012	Jan. 31, 2013
Summarized operating results and certain financial position data of Company's reportable continuing business segments
Net revenues	$ 46,648,000	$ 63,690,000
Cost of revenues	33,620,000	53,589,000
Gross profit	13,028,000	10,101,000
Selling, general and administrative expenses	3,443,000	3,028,000
Income (loss) from operations	9,585,000	7,073,000
Gain on deconsolidation of variable interest entity	1,120,000
Other income (expense), net	155,000	(9,000)
Income (loss) before income taxes	10,860,000	7,064,000
Income tax expense	3,920,000	2,517,000
Income from continuing operations	6,940,000	4,547,000
Amortization of purchased intangibles	61,000	61,000
Depreciation	129,000	117,000
Property, plant and equipment additions	684,000	1,164,000
Goodwill	18,476,000	18,476,000	18,476,000
Total assets	225,586,000	224,689,000	234,724,000
Power Industry Services [Member]
Summarized operating results and certain financial position data of Company's reportable continuing business segments
Net revenues	43,769,000	57,728,000
Cost of revenues	31,246,000	48,984,000
Gross profit	12,523,000	8,744,000
Selling, general and administrative expenses	1,815,000	1,558,000
Income (loss) from operations	10,708,000	7,186,000
Gain on deconsolidation of variable interest entity	1,120,000
Other income (expense), net	154,000	(9,000)
Income (loss) before income taxes	11,982,000	7,177,000
Amortization of purchased intangibles	61,000	61,000
Depreciation	83,000	58,000
Property, plant and equipment additions	673,000	1,026,000
Goodwill	18,476,000	18,476,000
Total assets	174,819,000	177,183,000
Telecommunications Infrastructure Services [Member]
Summarized operating results and certain financial position data of Company's reportable continuing business segments
Net revenues	2,879,000	5,962,000
Cost of revenues	2,374,000	4,605,000
Gross profit	505,000	1,357,000
Selling, general and administrative expenses	316,000	440,000
Income (loss) from operations	189,000	917,000
Income (loss) before income taxes	189,000	917,000
Depreciation	45,000	58,000
Property, plant and equipment additions	11,000	138,000
Total assets	3,503,000	4,819,000
Other [Member]
Summarized operating results and certain financial position data of Company's reportable continuing business segments
Selling, general and administrative expenses	1,312,000	1,030,000
Income (loss) from operations	(1,312,000)	(1,030,000)
Other income (expense), net	1,000
Income (loss) before income taxes	(1,311,000)	(1,030,000)
Depreciation	1,000	1,000
Total assets	$ 47,264,000	$ 42,687,000