Goodwill and Intangible Assets - Schedule of Finite-Lived and Indefinite-Lived Intangible Assets (Details) - USD ($) $ in Millions	3 Months Ended
	Sep. 30, 2024	Jun. 30, 2024	Mar. 31, 2024	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023
Finite-lived Intangible Assets [Roll Forward]
Amortization	$ (96.2)	$ (95.8)	$ (99.0)	$ (103.7)	$ (103.9)	$ (106.7)
Other indefinite-lived intangibles
Balance at beginning of period	1,280.0	1,280.0	1,280.0	1,280.0	1,280.0	1,280.0
Additions at cost	0.0	0.0	0.0	0.0	0.0	0.0
Other	0.0	0.0	0.0	0.0	0.0	0.0
Balance at end of period	1,280.0	1,280.0	1,280.0	1,280.0	1,280.0	1,280.0
Total
Balance at beginning of period	3,709.6	3,805.2	3,915.9	4,113.3	4,218.6	4,320.1
Additions at cost	0.1	0.3	0.1	0.1	0.1	0.1
Amortization	(96.2)	(95.8)	(99.0)	(103.7)	(103.9)	(106.7)
Other	15.9	(0.1)	(11.8)	(11.3)	(1.5)	5.1
Balance at end of period	3,629.4	3,709.6	3,805.2	3,998.4	4,113.3	4,218.6
Customer relationships
Finite-lived Intangible Assets [Roll Forward]
Balance at beginning of period	1,211.5	1,261.7	1,316.7	1,424.4	1,481.0	1,536.7
Additions at cost	0.0	0.0	0.0	0.0	0.0	0.0
Amortization	(50.7)	(50.5)	(52.4)	(55.0)	(55.1)	(56.8)
Other	3.2	0.3	(2.6)	(1.9)	(1.5)	1.1
Balance at end of period	1,164.0	1,211.5	1,261.7	1,367.5	1,424.4	1,481.0
Total
Amortization	(50.7)	(50.5)	(52.4)	(55.0)	(55.1)	(56.8)
Reacquired rights
Finite-lived Intangible Assets [Roll Forward]
Balance at beginning of period	217.4	222.8	233.9	238.8	243.6	245.5
Additions at cost	0.0	0.0	0.0	0.0	0.0	0.0
Amortization	(4.8)	(4.7)	(4.8)	(4.7)	(4.8)	(4.7)
Other	8.2	(0.7)	(6.3)	(6.6)	0.0	2.8
Balance at end of period	220.8	217.4	222.8	227.5	238.8	243.6
Total
Amortization	(4.8)	(4.7)	(4.8)	(4.7)	(4.8)	(4.7)
Database
Finite-lived Intangible Assets [Roll Forward]
Balance at beginning of period	864.3	900.5	940.6	1,017.6	1,059.1	1,100.0
Additions at cost	0.0	0.0	0.0	0.0	0.0	0.0
Amortization	(36.5)	(36.5)	(37.7)	(39.7)	(39.8)	(41.0)
Other	1.5	0.3	(2.4)	(0.7)	(1.7)	0.1
Balance at end of period	829.3	864.3	900.5	977.2	1,017.6	1,059.1
Total
Amortization	(36.5)	(36.5)	(37.7)	(39.7)	(39.8)	(41.0)
Other intangibles
Finite-lived Intangible Assets [Roll Forward]
Balance at beginning of period	136.4	140.2	144.7	152.5	154.9	157.9
Additions at cost	0.1	0.3	0.1	0.1	0.1	0.1
Amortization	(4.2)	(4.1)	(4.1)	(4.3)	(4.2)	(4.2)
Other	3.0	0.0	(0.5)	(2.1)	1.7	1.1
Balance at end of period	135.3	136.4	140.2	146.2	152.5	154.9
Total
Amortization	$ (4.2)	$ (4.1)	$ (4.1)	$ (4.3)	$ (4.2)	$ (4.2)