Consolidated Statements of Earnings - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2023	Jan. 01, 2023	Jan. 02, 2022
Income Statement [Abstract]
Revenue from services	$ 4,835.7	$ 4,965.4	$ 4,909.7
Cost of services	3,874.3	3,953.6	3,990.5
Gross profit	961.4	1,011.8	919.2
Selling, general and administrative expenses	934.7	943.5	870.6
Asset impairment charge	2.4	0.0	0.0
Goodwill impairment charge	0.0	41.0	0.0
Gain on sale of assets	0.0	(6.2)	0.0
Loss on disposal	0.0	18.7	0.0
Earnings from operations	24.3	14.8	48.6
Gain (loss) on investment in Persol Holdings	0.0	(67.2)	121.8
Gain on insurance settlement	0.0	0.0	19.0
Loss on currency translation from liquidation of subsidiary	0.0	(20.4)	0.0
Unrealized loss on forward contract	(3.6)	0.0	0.0
Other income (expense), net	4.2	1.6	(3.6)
Earnings (loss) before taxes and equity in net earnings of affiliate	24.9	(71.2)	185.8
Income tax expense (benefit)	(11.5)	(7.9)	35.1
Net earnings (loss) before equity in net earnings of affiliate	36.4	(63.3)	150.7
Equity in net earnings of affiliate	0.0	0.8	5.4
Net earnings (loss)	$ 36.4	$ (62.5)	$ 156.1
Basic earnings (loss) per share (in dollars per share)	$ 0.99	$ (1.64)	$ 3.93
Diluted earnings (loss) per share (in dollars per share)	$ 0.98	$ (1.64)	$ 3.91
Average shares outstanding (millions):
Basic (in shares)	35.9	38.1	39.4
Diluted (in shares)	36.3	38.1	39.5