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DESCRIPTION OF THE BUSINESS AND BASIS OF PRESENTATION (Details) $ in Thousands	3 Months Ended								12 Months Ended
	Jan. 31, 2018 USD ($)	Oct. 31, 2017 USD ($)	Jul. 31, 2017 USD ($)	Apr. 30, 2017 USD ($)	Jan. 31, 2017 USD ($)	Oct. 31, 2016 USD ($)	Jul. 31, 2016 USD ($)	Apr. 30, 2016 USD ($)	Jan. 31, 2018 USD ($) category	Jan. 31, 2017 USD ($)	Jan. 31, 2016 USD ($)
Description of the Business
Revenues	$ 169,578	$ 232,945	$ 259,803	$ 230,489	$ 206,760	$ 175,444	$ 162,495	$ 130,348	$ 892,815	$ 675,047	$ 413,275
Minimum
Description of the Business
Estimated useful lives of the assets									5 years
Maximum
Description of the Business
Estimated useful lives of the assets									39 years
Power Services
Description of the Business
Unapproved change orders contract amount	$ 9,300				$ 2,700				$ 9,300	2,700
Number of categories | category									2
Revenues									$ 814,544	$ 586,628	$ 387,636
Power Services | Minimum
Description of the Business
Revenue recognition period									3 months
Power Services | Maximum
Description of the Business
Revenue recognition period									3 years
GPS
Description of the Business
Consolidated revenues by subsidiaries									88.00%	85.00%	90.00%
Core services | Power Services
Description of the Business
Revenues									$ 814,544	$ 586,628	$ 383,378
Project development success fees | Power Services
Description of the Business
Revenues											$ 4,258

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.1)
-URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688

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