Goodwill and Intangible Assets - Other Intangibles (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Finite-lived Intangible Assets [Roll Forward]
Amortization	$ (99.0)	$ (106.7)
Other indefinite-lived intangibles
Balance at beginning of period	1,280.0	1,280.0
Additions at cost	0.0	0.0
Other	0.0	0.0
Balance at end of period	1,280.0	1,280.0
Total
Balance at beginning of period	3,915.9	4,320.1
Additions at cost	0.1	0.1
Amortization	(99.0)	(106.7)
Other	(11.8)	5.1
Balance at end of period	3,805.2	4,218.6
Customer relationships
Finite-lived Intangible Assets [Roll Forward]
Balance at beginning of period	1,316.7	1,536.7
Additions at cost	0.0	0.0
Amortization	(52.4)	(56.8)
Other	(2.6)	1.1
Balance at end of period	1,261.7	1,481.0
Total
Amortization	(52.4)	(56.8)
Reacquired rights
Finite-lived Intangible Assets [Roll Forward]
Balance at beginning of period	233.9	245.5
Additions at cost	0.0	0.0
Amortization	(4.8)	(4.7)
Other	(6.3)	2.8
Balance at end of period	222.8	243.6
Total
Amortization	(4.8)	(4.7)
Database
Finite-lived Intangible Assets [Roll Forward]
Balance at beginning of period	940.6	1,100.0
Additions at cost	0.0	0.0
Amortization	(37.7)	(41.0)
Other	(2.4)	0.1
Balance at end of period	900.5	1,059.1
Total
Amortization	(37.7)	(41.0)
Other intangibles
Finite-lived Intangible Assets [Roll Forward]
Balance at beginning of period	144.7	157.9
Additions at cost	0.1	0.1
Amortization	(4.1)	(4.2)
Other	(0.5)	1.1
Balance at end of period	140.2	154.9
Total
Amortization	$ (4.1)	$ (4.2)