Segment Reporting (Details) (USD $)	3 Months Ended		6 Months Ended
	Jul. 31, 2013	Jul. 31, 2012	Jul. 31, 2013	Jul. 31, 2012	Jan. 31, 2013
Summarized operating results and certain financial position data of Company's reportable continuing business segments
Net revenues	$ 57,864,000	$ 82,619,000	$ 104,512,000	$ 146,309,000
Cost of revenues	36,607,000	69,740,000	70,227,000	123,329,000
Gross profit	21,257,000	12,879,000	34,285,000	22,980,000
Selling, general and administrative expenses	1,601,000	3,297,000	5,044,000	6,325,000
Income (loss) from operations	19,656,000	9,582,000	29,241,000	16,655,000
Gains on the deconsolidation of VIEs	1,324,000		2,444,000
Other income (expense), net	410,000	(10,000)	566,000	(19,000)
Income (loss) from continuing operations before income taxes	21,390,000	9,572,000	32,251,000	16,636,000
Income tax expense	7,467,000	3,591,000	11,388,000	6,108,000
Income from continuing operations	13,923,000	5,981,000	20,863,000	10,528,000
Amortization of purchased intangibles	61,000	61,000	121,000	121,000
Depreciation	136,000	132,000	265,000	249,000
Property, plant and equipment additions	174,000	2,627,000	851,000	3,791,000
Goodwill	18,476,000	18,476,000	18,476,000	18,476,000	18,476,000
Total assets	206,748,000	245,463,000	206,748,000	245,463,000	234,724,000
Power Industry Services [Member]
Summarized operating results and certain financial position data of Company's reportable continuing business segments
Net revenues	55,520,000	78,109,000	99,289,000	135,837,000
Cost of revenues	34,804,000	66,182,000	66,050,000	115,166,000
Gross profit	20,716,000	11,927,000	33,239,000	20,671,000
Selling, general and administrative expenses	1,626,000	1,932,000	3,441,000	3,491,000
Income (loss) from operations	19,090,000	9,995,000	29,798,000	17,180,000
Gains on the deconsolidation of VIEs	1,324,000		2,444,000
Other income (expense), net	409,000	(11,000)	564,000	(20,000)
Income (loss) from continuing operations before income taxes	20,823,000	9,984,000	32,806,000	17,160,000
Amortization of purchased intangibles	61,000	61,000	121,000	121,000
Depreciation	89,000	69,000	172,000	127,000
Property, plant and equipment additions	141,000	2,591,000	807,000	3,617,000
Goodwill	18,476,000	18,476,000	18,476,000	18,476,000
Total assets	150,254,000	195,250,000	150,254,000	195,250,000
Telecommunications Infrastructure Services [Member]
Summarized operating results and certain financial position data of Company's reportable continuing business segments
Net revenues	2,344,000	4,510,000	5,223,000	10,472,000
Cost of revenues	1,803,000	3,558,000	4,177,000	8,163,000
Gross profit	541,000	952,000	1,046,000	2,309,000
Selling, general and administrative expenses	330,000	441,000	646,000	881,000
Income (loss) from operations	211,000	511,000	400,000	1,428,000
Income (loss) from continuing operations before income taxes	211,000	511,000	400,000	1,428,000
Depreciation	46,000	62,000	91,000	120,000
Property, plant and equipment additions	33,000	36,000	44,000	174,000
Total assets	2,718,000	4,117,000	2,718,000	4,117,000
Other [Member]
Summarized operating results and certain financial position data of Company's reportable continuing business segments
Selling, general and administrative expenses	(355,000)	924,000	957,000	1,953,000
Income (loss) from operations	355,000	(924,000)	(957,000)	(1,953,000)
Other income (expense), net	1,000	1,000	2,000	1,000
Income (loss) from continuing operations before income taxes	356,000	(923,000)	(955,000)	(1,952,000)
Depreciation	1,000	1,000	2,000	2,000
Total assets	$ 53,776,000	$ 46,096,000	$ 53,776,000	$ 46,096,000