CUSTOMER CONCENTRATIONS (Details) $ in Millions	3 Months Ended		12 Months Ended
	Apr. 30, 2018 USD ($) Owner customer	Apr. 30, 2017 customer	Jan. 31, 2018 USD ($)
Accounts Receivable
Customer Concentrations
Number of project owners | Owner	5
Major Customer One
Customer Concentrations
Amounts retained by project owners	$ 19.9		$ 19.3
Major Customer One | Accounts Receivable
Customer Concentrations
Percentage of consolidated accounts receivable accounted by major customer	33.00%		18.00%
Major Customer Two
Customer Concentrations
Amounts retained by project owners	$ 19.4		$ 18.7
Major Customer Two | Accounts Receivable
Customer Concentrations
Percentage of consolidated accounts receivable accounted by major customer			18.00%
Major Customer Three
Customer Concentrations
Amounts retained by project owners	14.6		$ 14.1
Major Customer Four
Customer Concentrations
Amounts retained by project owners	13.9		13.4
Major Customer Five
Customer Concentrations
Amounts retained by project owners	$ 4.1		$ 3.2
Power Services | Revenue
Customer Concentrations
Percentage of major customers or segments	87.00%	91.00%
Number of major power industry service customers | customer	4	4
Power Services | Major Customer One | Revenue
Customer Concentrations
Percentage of major customers or segments	22.00%	29.00%
Power Services | Major Customer Two | Revenue
Customer Concentrations
Percentage of major customers or segments	19.00%	21.00%
Power Services | Major Customer Three | Revenue
Customer Concentrations
Percentage of major customers or segments	12.00%	21.00%
Power Services | Major Customer Four | Revenue
Customer Concentrations
Percentage of major customers or segments	12.00%	18.00%