Segment Reporting (Details) (USD $)	3 Months Ended		9 Months Ended
	Oct. 31, 2012	Oct. 31, 2011	Oct. 31, 2012	Oct. 31, 2011	Jan. 31, 2012
Summarized operating results and certain financial position data of Company's reportable continuing business segments
Net revenues	$ 74,486,000	$ 43,597,000	$ 220,794,000	$ 85,932,000
Cost of revenues	61,350,000	37,130,000	184,678,000	70,920,000
Gross profit	13,136,000	6,467,000	36,116,000	15,012,000
Selling, general and administrative expenses	3,780,000	2,735,000	10,105,000	7,868,000
Income (loss) from operations	9,356,000	3,732,000	26,011,000	7,144,000
Other (expense) income, net	(11,000)	33,000	(29,000)	84,000
Income (loss) from continuing operations before income taxes	9,345,000	3,765,000	25,982,000	7,228,000
Income tax expense	3,632,000	1,460,000	9,741,000	2,658,000
Income from continuing operations	5,713,000	2,305,000	16,241,000	4,570,000
Amortization of purchased intangibles	61,000	87,000	182,000	262,000
Depreciation	136,000	112,000	385,000	344,000
Fixed asset additions	2,139,000	76,000	5,928,000	135,000
Goodwill	18,476,000	18,476,000	18,476,000	18,476,000	18,476,000
Total assets	254,985,000	189,301,000	254,985,000	189,301,000	205,252,000
Power Industry Services [Member]
Summarized operating results and certain financial position data of Company's reportable continuing business segments
Net revenues	70,527,000	41,269,000	206,364,000	79,678,000
Cost of revenues	58,173,000	35,248,000	173,339,000	65,807,000
Gross profit	12,354,000	6,021,000	33,025,000	13,871,000
Selling, general and administrative expenses	2,042,000	1,518,000	5,533,000	4,263,000
Income (loss) from operations	10,312,000	4,503,000	27,492,000	9,608,000
Other (expense) income, net	(12,000)	30,000	(31,000)	70,000
Income (loss) from continuing operations before income taxes	10,300,000	4,533,000	27,461,000	9,678,000
Amortization of purchased intangibles	61,000	87,000	182,000	262,000
Depreciation	77,000	53,000	205,000	153,000
Fixed asset additions	2,092,000	23,000	5,707,000	23,000
Goodwill	18,476,000	18,476,000	18,476,000	18,476,000
Total assets	198,531,000	153,573,000	198,531,000	153,573,000
Telecommunications Infrastructure Services [Member]
Summarized operating results and certain financial position data of Company's reportable continuing business segments
Net revenues	3,959,000	2,328,000	14,430,000	6,254,000
Cost of revenues	3,177,000	1,882,000	11,339,000	5,113,000
Gross profit	782,000	446,000	3,091,000	1,141,000
Selling, general and administrative expenses	452,000	423,000	1,333,000	1,159,000
Income (loss) from operations	330,000	23,000	1,758,000	(18,000)
Income (loss) from continuing operations before income taxes	330,000	23,000	1,758,000	(18,000)
Depreciation	58,000	58,000	178,000	188,000
Fixed asset additions	47,000	53,000	221,000	109,000
Total assets	3,995,000	2,783,000	3,995,000	2,783,000
Other [Member]
Summarized operating results and certain financial position data of Company's reportable continuing business segments
Selling, general and administrative expenses	1,286,000	794,000	3,239,000	2,446,000
Income (loss) from operations	(1,286,000)	(794,000)	(3,239,000)	(2,446,000)
Other (expense) income, net	1,000	3,000	2,000	14,000
Income (loss) from continuing operations before income taxes	(1,285,000)	(791,000)	(3,237,000)	(2,432,000)
Depreciation	1,000	1,000	2,000	3,000
Fixed asset additions				3,000
Total assets	$ 52,459,000	$ 32,945,000	$ 52,459,000	$ 32,945,000