Goodwill and Intangible Assets - Balances of Acquired Intangible Assets, Excluding Goodwill (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2024	Dec. 31, 2023
Finite-Lived Intangible Assets [Line Items]
Original cost	$ 206.5	$ 196.2
Accumulated amortization	(134.2)	(133.1)
Carrying value	72.3	63.1
Customer Lists
Finite-Lived Intangible Assets [Line Items]
Original cost	161.7	150.6
Accumulated amortization	(101.5)	(100.8)
Carrying value	$ 60.2	$ 49.8
Weighted average original life (in years)	14 years	15 years
Trade Names
Finite-Lived Intangible Assets [Line Items]
Original cost	$ 28.7	$ 29.3
Accumulated amortization	(19.5)	(19.2)
Carrying value	$ 9.2	$ 10.1
Weighted average original life (in years)	10 years	11 years
Technology
Finite-Lived Intangible Assets [Line Items]
Original cost	$ 16.1	$ 16.3
Accumulated amortization	(13.2)	(13.1)
Carrying value	$ 2.9	$ 3.2
Weighted average original life (in years)	12 years	11 years