Other Assets - Schedule of Other Assets (Details) - USD ($) $ in Millions	Dec. 29, 2024	Dec. 31, 2023	Jan. 01, 2023
Other Assets [Line Items]
Intangibles, net	$ 256.3	$ 137.7
Noncurrent restricted cash	6.4	8.0	$ 8.6
Workers' compensation and other claims receivable	4.9	11.7
Equity securities, FV-NI and without readily determinable fair value	11.0	7.9
Other	5.1	7.8
Total other assets	45.3	43.1
Total other assets, including held-for-sale		48.5
Intangible assets, accumulated amortization	91.4	64.1
PersolKelly Pte. Ltd.
Other Assets [Line Items]
Equity securities, FV-NI and without readily determinable fair value	6.4
Disposal Group, Held-for-Sale, Not Discontinued Operations | European Staffing Operations
Other Assets [Line Items]
Total other assets		5.4
Long Term Hosted Software, net of accumulated amortization
Other Assets [Line Items]
Intangibles, net	17.9	13.1
Long Term Hosted Software, net of accumulated amortization | Other Assets
Other Assets [Line Items]
Intangible assets, accumulated amortization	$ 23.5	$ 14.2