Goodwill and Other Intangible Assets - Schedule of Activity in Carrying Amount of Goodwill (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Dec. 30, 2023	Dec. 28, 2024	Dec. 30, 2023
Goodwill [Roll Forward]
Goodwill, gross beginning balance		$ 519.6	$ 371.1
Accumulated impairment losses, beginning balance		(78.6)	(65.2)
Goodwill, net beginning balance		441.0	305.9
Goodwill acquired / measurement period adjustments		1.1
Impairment losses			(27.6)
Goodwill disposed			(14.1)
Accumulated impairment losses disposed			14.1
Goodwill, gross ending balance	$ 519.6	520.7	519.6
Accumulated impairment losses, ending balance	(78.6)	(78.6)	(78.6)
Goodwill, net ending balance	441.0	442.1	441.0
Goodwill acquired / measurement period adjustments			162.7
Workplace Furnishings
Goodwill [Roll Forward]
Goodwill, gross beginning balance		297.2	148.7
Accumulated impairment losses, beginning balance		(78.5)	(65.0)
Goodwill, net beginning balance		218.7	83.6
Goodwill acquired / measurement period adjustments		1.1
Impairment losses	(27.6)		(27.6)
Goodwill disposed			(14.1)
Accumulated impairment losses disposed			14.1
Goodwill, gross ending balance	297.2	298.3	297.2
Accumulated impairment losses, ending balance	(78.5)	(78.5)	(78.5)
Goodwill, net ending balance	218.7	219.8	218.7
Goodwill acquired / measurement period adjustments			162.7
Residential Building Products
Goodwill [Roll Forward]
Goodwill, gross beginning balance		222.4	222.4
Accumulated impairment losses, beginning balance		(0.1)	(0.1)
Goodwill, net beginning balance		222.3	222.3
Goodwill acquired / measurement period adjustments		0.0
Impairment losses			0.0
Goodwill disposed			0.0
Accumulated impairment losses disposed			0.0
Goodwill, gross ending balance	222.4	222.4	222.4
Accumulated impairment losses, ending balance	(0.1)	(0.1)	(0.1)
Goodwill, net ending balance	$ 222.3	$ 222.3	222.3
Goodwill acquired / measurement period adjustments			$ 0.0