Income Taxes - Rollforward of Deferred Tax Assets Valuation Allowance (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Valuation Allowance [Line Items]
Deferred Tax Assets, Valuation Allowance, Beginning Balance	$ 102.4	$ 108.8	$ 123.0
Change in assessment	(39.5)	(1.1)	(1.9)
Current year operations	10.4	(5.3)	(12.3)
Deferred Tax Assets, Valuation Allowance, Ending Balance	73.3	102.4	108.8
State and Local Jurisdiction [Member]
Valuation Allowance [Line Items]
Deferred Tax Assets, Valuation Allowance, Beginning Balance	39.5	35.7	40.4
Change in assessment	(23.1)	0.0	0.0
Current year operations	(0.8)	3.8	(4.7)
Deferred Tax Assets, Valuation Allowance, Ending Balance	15.6	39.5	35.7
Foreign Tax Authority [Member]
Valuation Allowance [Line Items]
Deferred Tax Assets, Valuation Allowance, Beginning Balance	62.9	73.1	82.6
Change in assessment	(16.4)	(1.1)	(1.9)
Current year operations	11.2	(9.1)	(7.6)
Deferred Tax Assets, Valuation Allowance, Ending Balance	$ 57.7	$ 62.9	$ 73.1