Goodwill and Other Intangible Assets - Goodwill (Details) $ in Millions	9 Months Ended
	Sep. 30, 2023 USD ($)
Goodwill [Roll Forward]
Goodwill, gross, beginning balance	$ 371.1
Accumulated impairment losses	(65.2)
Goodwill, net, beginning balance	305.9
Goodwill acquired	189.6
Goodwill, gross, ending balance	560.7
Accumulated impairment losses	(65.2)
Goodwill, net, ending balance	495.6
Workplace furnishings
Goodwill [Roll Forward]
Goodwill, gross, beginning balance	148.7
Accumulated impairment losses	(65.0)
Goodwill, net, beginning balance	83.6
Goodwill acquired	189.6
Goodwill, gross, ending balance	338.3
Accumulated impairment losses	(65.0)
Goodwill, net, ending balance	273.3
Residential building products
Goodwill [Roll Forward]
Goodwill, gross, beginning balance	222.4
Accumulated impairment losses	(0.1)
Goodwill, net, beginning balance	222.3
Goodwill acquired	0.0
Goodwill, gross, ending balance	222.4
Accumulated impairment losses	(0.1)
Goodwill, net, ending balance	$ 222.3