Business Combinations, Goodwill and Other Intangible Assets, Other Intangibles by Segment (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Schedule of Finite and Indefinite lived Intangible Assets by Segment [Line Items]
Additions, net of adjustments	$ 101.8	$ 160.2
Adjustment for fully amortized intangibles	(61.4)	(76.8)
Impact of exchange rate movements	3.3	(6.2)
Intangible Assets, Gross (Excluding Goodwill)	1,348.0	1,304.3	$ 1,227.1
Identified intangibles, with finite useful lives, accumulated amortization	(563.0)	(445.8)	(340.1)
Amortization expense, net (1)	(177.7)	(184.8)
Accumulated Amortization Adjustment for fully Amortized Intangibles	61.4	76.8
Impact of exchange rate movements	(0.9)	(2.3)
Net book value as of end of period	785.0	858.5
Servicing Asset at Amortized Cost, Other than Temporary Impairments	10.0	28.0
Finite-Lived Intangible Assets, Amortization Expense, Maturity Schedule [Abstract]
2024	161.7
2025	132.6
2026	96.0
2027	79.1
2028	65.4
Thereafter	200.6
Total	735.4
Mortgage servicing rights [Member]
Schedule of Finite and Indefinite lived Intangible Assets by Segment [Line Items]
Additions, net of adjustments	94.6	140.9
Adjustment for fully amortized intangibles	(40.1)	(63.3)
Impact of exchange rate movements	0.0	0.0
Intangible Assets, Gross (Excluding Goodwill)	801.8	747.3	669.7
Identified intangibles, with finite useful lives, accumulated amortization	(309.8)	(242.2)	(191.0)
Amortization expense, net (1)	(107.7)	(114.5)
Accumulated Amortization Adjustment for fully Amortized Intangibles	40.1	63.3
Impact of exchange rate movements	0.0	0.0
Net book value as of end of period	$ 492.0	505.1
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	3 years 10 months 24 days
Finite-Lived Intangible Assets, Amortization Expense, Maturity Schedule [Abstract]
2024	$ 97.4
2025	88.7
2026	75.9
2027	64.4
2028	51.0
Thereafter	114.6
Total	492.0
Other Intangible Assets [Member]
Schedule of Finite and Indefinite lived Intangible Assets by Segment [Line Items]
Additions, net of adjustments	7.2	19.3
Adjustment for fully amortized intangibles	(21.3)	(13.5)
Impact of exchange rate movements	3.3	(6.2)
Intangible Assets, Gross (Excluding Goodwill)	546.2	557.0	557.4
Identified intangibles, with finite useful lives, accumulated amortization	(253.2)	(203.6)	$ (149.1)
Amortization expense, net (1)	(70.0)	(70.3)
Accumulated Amortization Adjustment for fully Amortized Intangibles	21.3	13.5
Impact of exchange rate movements	(0.9)	$ 2.3
Net book value as of end of period	$ 293.0
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	4 years 7 months 6 days
Finite-Lived Intangible Assets, Amortization Expense, Maturity Schedule [Abstract]
2024	$ 64.3
2025	43.9
2026	20.1
2027	14.7
2028	14.4
Thereafter	86.0
Total	$ 243.4

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