Commitments And Contingencies (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Feb. 29, 2016	Nov. 30, 2014	Aug. 31, 2012	May 31, 2016	Aug. 31, 2015	May 31, 2015
Commitments And Contingencies [Abstract]
Environmental remediation expense	$ 13,000	$ 1,500	$ 7,200
Estimated aggregate accrued cost				$ 19,551	$ 7,531	$ 7,594