Revenue from Contracts with Customers - Schedule of Disaggregation of Revenue (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jul. 04, 2026	Jun. 28, 2025	Jul. 04, 2026	Jun. 28, 2025
Disaggregation of Revenue [Line Items]
Net sales	$ 1,472.4	$ 667.1	$ 2,819.9	$ 1,266.8
Workplace furnishings
Disaggregation of Revenue [Line Items]
Net sales	1,323.7	516.0	2,509.2	957.0
Workplace furnishings \| Systems, storage, and tables
Disaggregation of Revenue [Line Items]
Net sales	594.9	322.0	1,157.8	597.2
Workplace furnishings \| Seating
Disaggregation of Revenue [Line Items]
Net sales	343.7	149.7	655.7	283.3
Workplace furnishings \| Education
Disaggregation of Revenue [Line Items]
Net sales	170.6	20.8	245.9	28.6
Workplace furnishings \| Other
Disaggregation of Revenue [Line Items]
Net sales	214.5	23.4	449.9	47.9
Residential building products
Disaggregation of Revenue [Line Items]
Net sales	$ 148.7	$ 151.1	$ 310.8	$ 309.8

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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+ Details

- Definition

Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.

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