Major Customers - Additional Information (Detail) (Power Industry Services [Member])	12 Months Ended
	Jan. 31, 2014 Customer	Jan. 31, 2013 Customer	Jan. 31, 2012 Customer
Revenue, Major Customer [Line Items]
Percentage of consolidated net revenue accounted by major segment	96.00%	94.00%	93.00%
Number of major power industry service customers	3	2	3
Major Customer One [Member]
Revenue, Major Customer [Line Items]
Percentage of consolidated net revenue accounted by major customers	33.00%	56.00%	43.00%
Major Customer Two [Member]
Revenue, Major Customer [Line Items]
Percentage of consolidated net revenue accounted by major customers	33.00%	18.00%	30.00%
Major Customer Three [Member]
Revenue, Major Customer [Line Items]
Percentage of consolidated net revenue accounted by major customers	22.00%		12.00%