Supplementary Data (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024	Dec. 31, 2024
Text Block [Abstract]
Goodwill	$ 4,756.1		$ 4,689.4
Goodwill, Acquired During Period	42.2
Goodwill, Other Decrease	24.5
Goodwill	4,756.1		4,689.4
Goodwill, Acquired During Period	42.2
Goodwill, Other Decrease	24.5
Severance and termination costs	80.1	$ 0.0
Other restructuring costs	52.9	0.0
Restructuring charges	203.3	0.6
Operating lease right-of-use asset	932.0		1,037.8
Goodwill, Impaired, Accumulated Impairment Loss	207.2
Payments to Acquire Businesses, Net of Cash Acquired	48.4	0.0
MD&E
Text Block [Abstract]
Goodwill	2,380.8		2,332.8
Goodwill, Acquired During Period	42.2
Goodwill, Other Decrease	5.8
Goodwill	2,380.8		2,332.8
Goodwill, Acquired During Period	42.2
Goodwill, Other Decrease	5.8
Severance and termination costs	0.7	22.2
Lease impairment costs	19.1
Restructuring charges	53.3	0.0
IA&C
Text Block [Abstract]
Goodwill	1,697.4		1,681.8
Goodwill, Acquired During Period	0.0
Goodwill, Other Decrease	15.6
Goodwill	1,697.4		1,681.8
Goodwill, Acquired During Period	0.0
Goodwill, Other Decrease	15.6
Severance and termination costs	1.9	20.3
Lease impairment costs	18.6	0.3
Restructuring charges	55.9	0.3
SC&E
Text Block [Abstract]
Goodwill	677.9		674.8
Goodwill, Acquired During Period	0.0
Goodwill, Other Decrease	3.1
Goodwill	677.9		$ 674.8
Goodwill, Acquired During Period	0.0
Goodwill, Other Decrease	3.1
Severance and termination costs	0.8	4.7
Lease impairment costs	9.4	0.3
Restructuring charges	$ 21.7	$ 0.3