Net Income Per Share (Computation Of Basic And Diluted Net Income Per Common Share Under Treasury Stock Method) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Nov. 27, 2021	Nov. 28, 2020
Net Income Per Share [Abstract]
Net income attributable to MSC Industrial as reported	$ 66,067	$ 38,454
Weighted-average shares outstanding for basic net income per share	55,530	55,659
Effect of dilutive securities	326	191
Weighted-average shares outstanding for diluted net income per share	55,856	55,850
Basic	$ 1.19	$ 0.69
Diluted	$ 1.18	$ 0.69
Potentially dilutive securities	434	1,332