Segment Reporting (Details) (USD $)	12 Months Ended
	Jan. 31, 2013	Jan. 31, 2012
Summarized operating results and certain financial position data of Company's reportable continuing business segments
Net revenues	$ 278,635,000	$ 141,850,000
Cost of revenues	228,500,000	118,748,000
Gross profit	50,135,000	23,102,000
Selling, general and administrative expenses	14,350,000	11,186,000
Income (loss) from operations	35,785,000	11,916,000
Other (expense) income, net	(43,000)	48,000
Income (loss) from continuing operations before income taxes	35,742,000	11,964,000
Income tax expense	13,640,000	4,556,000
Income from continuing operations	22,102,000	7,408,000
Amortization of purchased intangible assets	243,000	334,000
Depreciation	522,000	455,000
Fixed asset additions	7,263,000	1,738,000
Goodwill	18,476,000	18,476,000
Total assets	234,724,000	205,252,000
Power Industry Services [Member]
Summarized operating results and certain financial position data of Company's reportable continuing business segments
Net revenues	261,327,000	132,519,000
Cost of revenues	214,817,000	111,193,000
Gross profit	46,510,000	21,326,000
Selling, general and administrative expenses	7,950,000	6,235,000
Income (loss) from operations	38,560,000	15,091,000
Other (expense) income, net	(45,000)	33,000
Income (loss) from continuing operations before income taxes	38,515,000	15,124,000
Amortization of purchased intangible assets	243,000	334,000
Depreciation	290,000	207,000
Fixed asset additions	6,986,000	1,598,000
Goodwill	18,476,000	18,476,000
Total assets	186,284,000	164,049,000
Telecommunications Infrastructure Services [Member]
Summarized operating results and certain financial position data of Company's reportable continuing business segments
Net revenues	17,308,000	9,331,000
Cost of revenues	13,683,000	7,555,000
Gross profit	3,625,000	1,776,000
Selling, general and administrative expenses	1,628,000	1,586,000
Income (loss) from operations	1,997,000	190,000
Income (loss) from continuing operations before income taxes	1,997,000	190,000
Depreciation	229,000	244,000
Fixed asset additions	277,000	136,000
Total assets	4,032,000	3,121,000
Other [Member]
Summarized operating results and certain financial position data of Company's reportable continuing business segments
Selling, general and administrative expenses	4,772,000	3,365,000
Income (loss) from operations	(4,772,000)	(3,365,000)
Other (expense) income, net	2,000	15,000
Income (loss) from continuing operations before income taxes	(4,770,000)	(3,350,000)
Depreciation	3,000	4,000
Fixed asset additions	0	4,000
Total assets	$ 44,408,000	$ 38,082,000