Acquisitions - Pro Forma Information (Details) (Nuclear Logistics Incorporated [Member], USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Feb. 28, 2013	Feb. 29, 2012
Nuclear Logistics Incorporated [Member]
Summary of acquisitions
Net Sales	$ 583,743	$ 522,678
Net Income	$ 60,602	$ 43,283
Earnings Per Common Share
Basic Earnings Per Share (usd per share)	$ 2.39	$ 1.72
Diluted Earnings Per Share (usd per share)	$ 2.37	$ 1.71