Summary of Significant Accounting Policies Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Aug. 31, 2018	Aug. 31, 2017	Aug. 31, 2018	Aug. 31, 2017
Disaggregation of Revenue [Line Items]
Revenue, Net	$ 222,787	$ 196,329	$ 485,023	$ 401,612
Industrial [Member]
Disaggregation of Revenue [Line Items]
Revenue, Net	120,305	115,834	271,613	228,919
Trasmission & Distribution [Member]
Disaggregation of Revenue [Line Items]
Revenue, Net	60,152	41,229	126,106	84,339
Power Generation [Member]
Disaggregation of Revenue [Line Items]
Revenue, Net	$ 42,330	$ 39,266	$ 87,304	$ 88,354