Segment Data - Schedule of Segment Data (Parenthetical) (Details) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Segment Reporting Information [Line Items]
Revenues from services	[1]	$ 4,856.1	$ 5,074.1	$ 9,608.4	$ 10,217.4
Franchise revenue		250.6	275.6	500.8	540.8
Franchise fees
Segment Reporting Information [Line Items]
Revenues from services		3.3	3.9	7.2	7.5
Americas
Segment Reporting Information [Line Items]
Revenues from services		1,098.7	1,262.7	2,228.9	2,513.9
Americas | United States
Segment Reporting Information [Line Items]
Revenues from services		736.7	903.9	1,506.7	1,793.3
Americas | United States | Franchise fees
Segment Reporting Information [Line Items]
Revenues from services		2.6	3.1	5.8	6.0
Franchise revenue		$ 100.8	$ 128.1	$ 200.1	$ 238.9

[1] Our consolidated revenues from services include fees received from our franchise offices of $3.3 and $3.9 for the three months ended June 30, 2023 and 2022, respectively, and $7.2 and $7.5 for the six months ended June 30, 2023 and 2022, respectively. These fees are primarily based on revenues generated by the franchise offices, which were $250.6 and $275.6 for the three months ended June 30, 2023 and 2022, respectively, and $500.8 and $540.8 for the six months ended June 30, 2023 and 2022, respectively.