Condensed Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	3 Months Ended
	Nov. 30, 2020	Nov. 30, 2019
Statement Of Income And Comprehensive Income [Abstract]
Net income (loss)	$ 15,064	$ (6,565)
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustments	239	211
Pension obligations, net	(260)	27
Total other comprehensive (loss) income, net of tax	(21)	238
Comprehensive income (loss)	15,043	(6,327)
Less comprehensive income attributable to noncontrolling interests	(960)	(430)
Comprehensive income (loss) attributable to SSI shareholders	$ 14,083	$ (6,757)