Summary of Significant Accounting Policies - Disaggregated Revenues (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Feb. 29, 2020	Nov. 30, 2019	Aug. 31, 2019	May 31, 2019	Feb. 28, 2019	Nov. 30, 2018	Aug. 31, 2018	May 31, 2018	Feb. 29, 2020	Feb. 28, 2019	Feb. 28, 2018
Disaggregation of Revenue [Line Items]
Revenues	$ 245,365	$ 291,139	$ 236,190	$ 289,123	$ 202,548	$ 239,516	$ 222,787	$ 262,236	$ 1,061,817	$ 927,087	$ 810,430
Industrial [Member]
Disaggregation of Revenue [Line Items]
Revenues									605,236	526,465	461,945
Trasmission & Distribution [Member]
Disaggregation of Revenue [Line Items]
Revenues									254,836	212,433	194,503
Power Generation [Member]
Disaggregation of Revenue [Line Items]
Revenues									$ 201,745	$ 188,189	$ 153,982