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Major Customers - Additional Information (Detail) (Power Industry Services [Member]) | 3 Months Ended | 9 Months Ended
--- | --- | ---
Oct. 31, 2014 Customer | Oct. 31, 2013 Customer | Oct. 31, 2014 Customer | Oct. 31, 2013 Customer
Revenue, Major Customer [Line Items] |  |  |  |
Percentage of consolidated net revenue accounted by major segment | 99.00% | 96.00% | 98.00% | 95.00%
Number of major power industry service customers | 3 | 2 | 3 | 3
Major Customer One [Member] | Revenue [Member] |  |  |  |
Revenue, Major Customer [Line Items] |  |  |  |
Percentage of consolidated net revenue accounted by major customers | 44.00% | 49.00% | 45.00% | 36.00%
Major Customer Two [Member] | Revenue [Member] |  |  |  |
Revenue, Major Customer [Line Items] |  |  |  |
Percentage of consolidated net revenue accounted by major customers | 44.00% | 29.00% | 39.00% | 30.00%
Major Customer Three [Member] | Revenue [Member] |  |  |  |
Revenue, Major Customer [Line Items] |  |  |  |
Percentage of consolidated net revenue accounted by major customers | 10.00% |  | 14.00% | 20.00%

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