Goodwill and Other Intangibles - Goodwill (Details)	3 Months Ended		9 Months Ended	12 Months Ended
	Aug. 31, 2019 USD ($) segment item	Feb. 28, 2019 USD ($)	May 31, 2019 USD ($) item	Aug. 31, 2019 USD ($) segment item	Aug. 31, 2018 USD ($)
Changes in the carrying value of goodwill
Balance at the beginning of the period			$ 84,696,000	$ 84,696,000	$ 50,784,000
Loss on impairment of polyurethane dispersions business	$ 0	$ (2,410,000)		(2,410,000)
Acquisition of Zappa Stewart					34,138,000
Sale of the fiber optic cable components business					(230,000)
Foreign currency translation adjustment				(300,000)	4,000
Balance at the end of the period	$ 81,986,000			$ 81,986,000	84,696,000
Number of operating segments | segment	3			3
Number of reporting units | item	3		12	3
Adhesives, Sealants and Additives
Changes in the carrying value of goodwill
Balance at the beginning of the period			$ 52,787,000	$ 52,787,000	18,646,000
Loss on impairment of polyurethane dispersions business				(2,410,000)
Acquisition of Zappa Stewart					34,138,000
Foreign currency translation adjustment				(287,000)	3,000
Balance at the end of the period	$ 50,090,000			50,090,000	52,787,000
Industrial Tapes
Changes in the carrying value of goodwill
Balance at the beginning of the period			21,215,000	21,215,000	21,445,000
Sale of the fiber optic cable components business					(230,000)
Balance at the end of the period	21,215,000			21,215,000	21,215,000
Corrosion Protection and Waterproofing
Changes in the carrying value of goodwill
Balance at the beginning of the period			$ 10,694,000	10,694,000	10,693,000
Foreign currency translation adjustment				(13,000)	1,000
Balance at the end of the period	$ 10,681,000			$ 10,681,000	$ 10,694,000