SEGMENT REPORTING (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Jan. 31, 2016	Oct. 31, 2015	Jul. 31, 2015	Apr. 30, 2015	Jan. 31, 2015	Oct. 31, 2014	Jul. 31, 2014	Apr. 30, 2014	Jan. 31, 2016	Jan. 31, 2015	Jan. 31, 2014
Segment Reporting Information
Revenues	$ 116,386	$ 113,967	$ 97,434	$ 85,488	$ 102,325	$ 127,564	$ 102,030	$ 51,191	$ 413,275	$ 383,110	$ 227,455
Cost of revenues									313,810	299,507	148,607
Gross profit	23,543	26,262	28,493	21,167	21,675	30,313	21,564	10,051	99,465	83,603	78,848
Selling, general and administrative expenses									25,060	19,470	12,918
Income (loss) from operations	14,461	20,672	23,645	15,627	15,538	24,840	17,083	6,672	74,405	64,133	65,930
Gains on deconsolidations									349		2,444
Other income, net									752	234	961
Income (loss) before income taxes									75,506	64,367	69,335
Income tax expense									25,302	20,912	25,991
Net income	9,160	$ 14,359	$ 15,834	$ 10,851	9,876	$ 16,759	$ 12,020	$ 4,800	50,204	43,455	43,344
Amortization of intangibles									531	243	243
Depreciation									779	551	549
Fixed asset additions									3,118	2,936	1,136
Current assets	351,723				364,354				351,723	364,354
Current liabilities	187,712				215,432				187,712	215,432
Goodwill	37,405				18,476				37,405	18,476	18,476
Total assets	410,902				391,193				410,902	391,193	323,306
Power Industry Services
Segment Reporting Information
Revenues									387,636	376,676	218,649
Cost of revenues									290,823	294,643	141,807
Gross profit									96,813	82,033	76,842
Selling, general and administrative expenses									15,303	11,930	7,575
Income (loss) from operations									81,510	70,103	69,267
Gains on deconsolidations									349		2,444
Other income, net									478	231	958
Income (loss) before income taxes									82,337	70,334	72,669
Amortization of intangibles									415	243	243
Depreciation									433	372	366
Fixed asset additions									2,985	2,807	1,067
Current assets	245,331								245,331
Current liabilities	160,782								160,782
Goodwill	22,525				18,476				22,525	18,476	18,476
Total assets	274,627				303,737				274,627	303,737	276,744
Telecommunications Infrastructure Services
Segment Reporting Information
Revenues									10,379	6,434	8,806
Cost of revenues									7,460	4,864	6,800
Gross profit									2,919	1,570	2,006
Selling, general and administrative expenses									1,323	1,299	1,331
Income (loss) from operations									1,596	271	675
Income (loss) before income taxes									1,596	271	675
Depreciation									162	169	180
Fixed asset additions									100	77	69
Current assets	1,340								1,340
Current liabilities	554								554
Total assets	1,885				2,293				1,885	2,293	1,989
Industrial Fabrication And Field Services
Segment Reporting Information
Revenues									15,260
Cost of revenues									15,527
Gross profit									(267)
Selling, general and administrative expenses									1,151
Income (loss) from operations									(1,418)
Income (loss) before income taxes									(1,418)
Amortization of intangibles									116
Depreciation									172
Fixed asset additions									28
Current assets	23,200								23,200
Current liabilities	24,351								24,351
Goodwill	14,880								14,880
Total assets	52,436								52,436
Other
Segment Reporting Information
Selling, general and administrative expenses									7,283	6,241	4,012
Income (loss) from operations									(7,283)	(6,241)	(4,012)
Other income, net									274	3	3
Income (loss) before income taxes									(7,009)	(6,238)	(4,009)
Depreciation									12	10	3
Fixed asset additions									5	52
Current assets	81,852								81,852
Current liabilities	2,025								2,025
Total assets	$ 81,954				$ 85,163				$ 81,954	$ 85,163	$ 44,573