Exit Costs Related to Idle Facility (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	May 31, 2017	May 31, 2016	May 31, 2017	May 31, 2016	Aug. 31, 2016
Exit Costs Related to Idle Facility
Acquisition related costs (Note 14)				$ 365
Exit and demolition costs		$ 662	$ 50	871
Randolph MA
Exit Costs Related to Idle Facility
Exit and demolition costs	$ 0	$ 662	$ 50	$ 871	$ 935