Acquisitions - Additional Information (Details) $ / shares in Units, $ in Millions		3 Months Ended	12 Months Ended
	Jul. 19, 2021 USD ($) $ / shares	Aug. 28, 2021 USD ($)	May 28, 2022 USD ($)	Sep. 03, 2022 USD ($)
Business Acquisition [Line Items]
Goodwill			$ 1,226.2	$ 1,197.5
Knoll
Business Acquisition [Line Items]
Transaction costs		$ 26.7	$ 30.0
Number of shares of Herman Miller, Inc. (now MillerKnoll, Inc.) stock to be issued for each issued and outstanding share of Knoll	0.32
Business acquisition, share price (in dollar per share) | $ / shares	$ 11.00
Total acquisition date fair value of consideration transferred	$ 1,887.3
Aggregate cash paid to acquire business	1,176.6
Fair value of replacement share awards	53.4
Amount preliminarily allocated to purchase price	22.4
Amount allocated to future services and to be expensed over remaining service periods	31.0
Goodwill	903.5
Knoll | Knoll
Business Acquisition [Line Items]
Goodwill	$ 903.5