CONCENTRATIONS OF REVENUES AND ACCOUNTS RECEIVABLE (Details) - customer
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3 Months Ended |
12 Months Ended |
Apr. 30, 2017 |
Apr. 30, 2016 |
Jan. 31, 2017 |
| Accounts Receivable |
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| Major Customers |
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| Number of major power industry service customers |
4
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4
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| Major Customer One | Accounts Receivable |
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| Major Customers |
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| Percentage of consolidated accounts receivable accounted by major customer |
18.00%
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|
18.00%
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| Major Customer Two | Accounts Receivable |
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| Major Customers |
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| Percentage of consolidated accounts receivable accounted by major customer |
17.00%
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|
17.00%
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| Major Customer Three | Accounts Receivable |
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| Major Customers |
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| Percentage of consolidated accounts receivable accounted by major customer |
15.00%
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|
17.00%
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| Major Customer Four | Accounts Receivable |
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| Major Customers |
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| Percentage of consolidated accounts receivable accounted by major customer |
12.00%
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|
11.00%
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| Power Services | Revenue |
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| Major Customers |
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| Percentage of major customers or segments |
91.00%
|
83.00%
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| Number of major power industry service customers |
4
|
5
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| Power Services | Major Customer One | Revenue |
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| Major Customers |
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| Percentage of major customers or segments |
29.00%
|
18.00%
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| Power Services | Major Customer Two | Revenue |
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| Major Customers |
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| Percentage of major customers or segments |
21.00%
|
15.00%
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| Power Services | Major Customer Three | Revenue |
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| Major Customers |
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| Percentage of major customers or segments |
21.00%
|
15.00%
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| Power Services | Major Customer Four | Revenue |
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| Major Customers |
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| Percentage of major customers or segments |
18.00%
|
12.00%
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| Power Services | Major Customer Five | Revenue |
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| Major Customers |
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| Percentage of major customers or segments |
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10.00%
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