Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	1 Months Ended	2 Months Ended	3 Months Ended						7 Months Ended	9 Months Ended
	Aug. 11, 2023	Sep. 30, 2023	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Aug. 11, 2023	Sep. 30, 2022
Beginning Balance	$ (327.5)	$ 0.0	$ (327.5)	$ (353.7)	$ (360.0)	$ (412.2)	$ (365.4)	$ (378.5)	$ (360.0)	$ (378.5)
Other comprehensive income (loss) before reclassifications	6.4	(35.8)		25.4	5.0	(37.5)	(46.9)	13.0
Amounts reclassified from AOCI	1.1	0.0		0.8	1.3	12.9	(0.1)	(0.1)	3.2	13.1
Net current-period other comprehensive income (loss)	327.5	(35.8)		26.2	6.3	(24.6)	(46.8)	13.1
Ending Balance	0.0	(35.8)	(35.8)	(327.5)	(353.7)	(436.8)	(412.2)	(365.4)	0.0	(436.8)
Translation attributable to noncontrolling interests	3.3		(0.2)	6.6	(2.2)	(1.9)	(2.3)	(0.8)
Translation adjustment
Beginning Balance	(322.2)	0.0	(322.2)	(347.4)	(352.1)	(350.1)	(300.5)	(310.9)	(352.1)	(310.9)
Other comprehensive income (loss) before reclassifications	(1.2)	(35.8)		25.2	4.7	(38.1)	(49.6)	10.4
Amounts reclassified from AOCI	0.0	0.0		0.0	0.0	0.0	0.0	0.0
Net current-period other comprehensive income (loss)	322.2	(35.8)		25.2	4.7	(38.1)	(49.6)	10.4
Ending Balance	0.0	(35.8)	(35.8)	(322.2)	(347.4)	(388.2)	(350.1)	(300.5)	0.0	(388.2)
Foreign Currency Hedges
Beginning Balance	(1.9)	0.0	(1.9)	(1.9)	(1.9)	(2.0)	(2.9)	(1.9)	(1.9)	(1.9)
Other comprehensive income (loss) before reclassifications	4.7	0.0		0.0	0.0	0.1	0.9	(1.0)
Amounts reclassified from AOCI	0.0	0.0		0.0	0.0	0.0	0.0	0.0
Net current-period other comprehensive income (loss)	1.9	0.0		0.0	0.0	0.1	0.9	(1.0)
Ending Balance	0.0	0.0	0.0	(1.9)	(1.9)	(1.9)	(2.0)	(2.9)	0.0	(1.9)
Interest Rate Hedges
Beginning Balance	5.8	0.0	5.8	5.6	5.3	4.5	2.7	0.4	5.3	0.4
Other comprehensive income (loss) before reclassifications	2.9	0.0		0.2	0.3	0.5	1.8	2.9
Amounts reclassified from AOCI	0.0	0.0		0.0	0.0	0.0	0.0	0.6
Net current-period other comprehensive income (loss)	(5.8)	0.0		0.2	0.3	0.5	1.8	2.3
Ending Balance	0.0	0.0	0.0	5.8	5.6	5.0	4.5	2.7	0.0	5.0
Pension and Other Post-retirement Benefits
Beginning Balance	(10.5)	0.0	(10.5)	(11.3)	(12.6)	(63.8)	(63.9)	(64.6)	(12.6)	(64.6)
Other comprehensive income (loss) before reclassifications	0.0	0.0		0.0	0.0	0.0	0.0	0.0
Amounts reclassified from AOCI		0.0		0.8	1.3	12.9	(0.1)	(0.7)
Net current-period other comprehensive income (loss)	10.5	0.0		0.8	1.3	12.9	0.1	0.7
Ending Balance	0.0	0.0	0.0	(10.5)	(11.3)	(50.9)	(63.8)	(63.9)	0.0	(50.9)
Other
Beginning Balance	1.3	0.0	1.3	1.3	1.3	(0.8)	(0.8)	(1.5)	1.3	(1.5)
Other comprehensive income (loss) before reclassifications	0.0	0.0		0.0	0.0	0.0	0.0	0.7
Amounts reclassified from AOCI	0.0	0.0		0.0	0.0	0.0	0.0	0.0
Net current-period other comprehensive income (loss)	(1.3)	0.0		0.0	0.0	0.0	0.0	0.7
Ending Balance	$ 0.0	$ 0.0	$ 0.0	$ 1.3	$ 1.3	$ (0.8)	$ (0.8)	$ (0.8)	$ 0.0	$ (0.8)