Income Tax - Reconciliation of Statutory Federal Income Tax Rate (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Effective Income Tax Rate Reconciliation, Percent [Abstract]
Statutory federal income tax rate		21.00%	21.00%	21.00%
Statutory federal income tax rate		$ (13.1)	$ 260.2	$ (135.2)
State income taxes, net of federal benefits		6.10%	4.70%	(1.70%)
State income taxes, net of federal benefits		$ (3.8)	$ 57.8	$ 11.0
Effect of foreign tax rates		92.60%	(5.50%)	3.50%
Effect of foreign tax rates		$ (57.9)	$ (68.3)	$ (22.3)
Effect of foreign tax law and rate changes		(0.80%)	1.60%	(0.90%)
Effect of foreign tax law and rate changes		$ 0.5	$ 19.6	$ 6.0
Effect of unrecognized tax benefits		(20.50%)	(6.20%)	(26.10%)
Effect of unrecognized tax benefits	$ (73.0)	$ 12.8	$ (76.3)	$ 167.9
Change in valuation allowance		1.10%	(0.10%)	1.30%
Change in valuation allowance		$ (0.7)	$ (1.1)	$ (8.4)
Goodwill impairment		(287.00%)	(0.20%)	(41.40%)
Goodwill impairment		$ 179.3	$ (2.9)	$ 266.8
Other, net		(10.90%)	3.30%	(2.60%)
Other, net		$ 6.9	$ 41.5	$ 16.0
Effective tax rate / Tax (benefit) expense		(198.40%)	18.60%	(46.90%)
Total income tax (benefit) expense		$ 124.0	$ 230.5	$ 301.8