Commitments and Contingencies (Summary of Undiscounted Environmental Remediation Liability Classifications) (Details) - USD ($) $ in Thousands	Feb. 29, 2020	Aug. 31, 2019	Feb. 28, 2019
Commitments And Contingencies Disclosure [Abstract]
Other current liabilities	$ 1,243	$ 1,243	$ 1,243
Other noncurrent liabilities	14,396	14,674	14,993
Total environmental remediation liabilities	$ 15,639	$ 15,917	$ 16,236

Carrying value of the obligation (known or estimated) arising from requirements to perform activities to remediate one or more sites, payable in twelve months or in the next operating cycle if longer.

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