Condensed Consolidated Statements Of Shareholders' Equity - USD ($) $ in Thousands	Class A Common Stock [Member] Common Stock [Member]	Class A Common Stock [Member] Retained Earnings [Member]	Class A Common Stock [Member] Treasury Stock [Member]	Class A Common Stock [Member]	Class B Common Stock [Member] Common Stock [Member]	Class B Common Stock [Member] Retained Earnings [Member]	Class B Common Stock [Member]	Additional Paid-In-Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Loss [Member]	Treasury Stock [Member]	Total Shareholders' Equity Attributable to MSC Industrial [Member]	Noncontrolling Interest [Member]	Total
Balance, Value at Sep. 01, 2018	$ 55				$ 10			$ 657,749	$ 1,325,822	$ (19,634)	$ (576,748)
Issuance of Noncontrolling Interest in MSC Mexico													$ 4,637
Capital Contributions													1,022
Foreign Currency Translation Adjustment										(603)			(63)	$ (666)
Net Income									142,656				6	142,656
Repurchase and retirement of common stock, Value	(1)							(11,887)	(48,439)
Associate Incentive Plans								24,185			1,243
Repurchases of common stock, Value			$ (24,098)
Cash dividends on common stock		$ (56,707)				$ (12,844)
Dividend equivalents declared, net of cancellations									(516)
Balance, Value at Mar. 02, 2019	54				10			670,047	1,349,972	(20,237)	(599,603)	$ 1,400,243	5,602	1,405,845
Dividends declared per common share				$ 1.26			$ 1.26
Balance, Value at Dec. 01, 2018	54				10			660,185	1,316,489	(20,975)	(579,451)
Issuance of Noncontrolling Interest in MSC Mexico													4,637
Capital Contributions													1,022
Foreign Currency Translation Adjustment										738			(63)	675
Net Income									68,424				6	68,424
Repurchase and retirement of common stock, Value
Associate Incentive Plans								9,862			746
Repurchases of common stock, Value			(20,898)
Cash dividends on common stock		(28,271)				(6,422)
Dividend equivalents declared, net of cancellations									(248)
Balance, Value at Mar. 02, 2019	54				10			670,047	1,349,972	(20,237)	(599,603)	1,400,243	5,602	1,405,845
Dividends declared per common share				0.63			0.63
Balance, Value at Aug. 31, 2019	46				10			659,226	946,651	(22,776)	(104,607)		5,329	1,483,879
Foreign Currency Translation Adjustment										723			95	818
Net Income									120,918				90	120,918
Repurchase and retirement of common stock, Value
Associate Incentive Plans	1							22,431			2,057
Repurchases of common stock, Value			(3,208)
Cash dividends on common stock		(294,923)				(65,892)
Dividend equivalents declared, net of cancellations									(3,358)
Balance, Value at Feb. 29, 2020	47				10			681,657	703,396	(22,053)	(105,758)	1,257,299	5,514	1,262,813
Dividends declared per common share				6.50			6.50
Balance, Value at Nov. 30, 2019	46				10			668,668	970,139	(21,310)	(106,690)		5,503
Foreign Currency Translation Adjustment										(743)			(45)	(788)
Net Income									55,500				56	55,500
Repurchase and retirement of common stock, Value
Associate Incentive Plans	1							12,989			1,131
Repurchases of common stock, Value			$ (199)
Cash dividends on common stock		$ (261,032)				$ (58,247)
Dividend equivalents declared, net of cancellations									(2,964)
Balance, Value at Feb. 29, 2020	$ 47				$ 10			$ 681,657	$ 703,396	$ (22,053)	$ (105,758)	$ 1,257,299	$ 5,514	$ 1,262,813
Dividends declared per common share				$ 5.75			$ 5.75