Goodwill and Other Intangibles - Goodwill (Details) $ in Thousands	3 Months Ended			9 Months Ended
	May 31, 2020 USD ($) segment	Aug. 31, 2019 USD ($) segment	May 31, 2019 USD ($)	May 31, 2020 USD ($) segment item	May 31, 2019 USD ($)
Changes in the carrying value of goodwill
Balance at the beginning of the period				$ 81,986
Foreign currency translation adjustment				58
Balance at the end of the period	$ 82,044	$ 81,986		$ 82,044
Number of operating segments | segment	3	2		3
Number of reporting units | item				3
Loss on impairment of goodwill (Note 7)					$ 2,410
Adhesives, Sealants and Additives
Changes in the carrying value of goodwill
Balance at the beginning of the period				$ 50,090
Foreign currency translation adjustment				55
Balance at the end of the period	$ 50,145	$ 50,090		50,145
Loss on impairment of goodwill (Note 7)			$ 2,410		$ 2,410
Industrial Tapes
Changes in the carrying value of goodwill
Balance at the beginning of the period				21,215
Balance at the end of the period	21,215	21,215		21,215
Corrosion Protection and Waterproofing
Changes in the carrying value of goodwill
Balance at the beginning of the period				10,681
Foreign currency translation adjustment				3
Balance at the end of the period	$ 10,684	$ 10,681		$ 10,684