Accumulated Other Comprehensive Income (Loss) - Reclasses Out Of AOCI (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Accumulated Other Comprehensive Income [Abstract]
Beginning Balance		$ 252.6	$ 202.5	$ 207.6
Other comprehensive income (loss)		201.0	89.5	(16.2)
Acquisitions of noncontrolling interests(c)	[1]	(7.8)
Ending Balance		570.2	252.6	202.5
Benefit plan adjustments
Accumulated Other Comprehensive Income [Abstract]
Beginning Balance		(474.0)	(614.8)	(583.0)
Other comprehensive income (loss) before reclassifications		151.9	92.5	(75.8)
Amounts reclassified from accumulated other comprehensive loss to net income (loss)		31.4	48.3	44.0
Other comprehensive income (loss)		183.3	140.8	(31.8)
Ending Balance		(290.7)	(474.0)	(614.8)
Foreign Currency Translation Adjustments
Accumulated Other Comprehensive Income [Abstract]
Beginning Balance		(425.7)	(363.2)	(382.8)
Other comprehensive income (loss) before reclassifications		(3.8)	(59.4)	19.6
Amounts reclassified from accumulated other comprehensive loss to net income (loss)		(4.4)	(3.1)	0.0
Other comprehensive income (loss)		(8.2)	(62.5)	19.6
Acquisitions of noncontrolling interests(c)		0.1
Ending Balance		(433.8)	(425.7)	(363.2)
Unrealized Gains (Losses) on Available-for-Sale Securities
Accumulated Other Comprehensive Income [Abstract]
Beginning Balance		(0.1)	0.0	0.0
Other comprehensive income (loss) before reclassifications		(0.7)	(0.1)	0.0
Amounts reclassified from accumulated other comprehensive loss to net income (loss)		0.2	0.0	0.0
Other comprehensive income (loss)		(0.5)	(0.1)	0.0
Ending Balance		(0.6)	(0.1)	0.0
Gains (Losses) on Cash Flow Hedges
Accumulated Other Comprehensive Income [Abstract]
Beginning Balance		(8.1)	(22.0)	(13.2)
Other comprehensive income (loss) before reclassifications		24.4	5.6	(1.4)
Amounts reclassified from accumulated other comprehensive loss to net income (loss)		8.3	8.3	(7.4)
Other comprehensive income (loss)		32.7	13.9	(8.8)
Ending Balance		24.6	(8.1)	(22.0)
AOCI Attributable to Parent
Accumulated Other Comprehensive Income [Abstract]
Beginning Balance		(907.9)	(1,000.0)	(979.0)
Other comprehensive income (loss) before reclassifications		171.8	38.6	(57.6)
Amounts reclassified from accumulated other comprehensive loss to net income (loss)		35.5	53.5	36.6
Other comprehensive income (loss)		207.3	92.1	(21.0)
Acquisitions of noncontrolling interests(c)	[1]	0.1
Ending Balance		$ (700.5)	$ (907.9)	$ (1,000.0)

[1] This amount represents the impact of transactions in which we acquired or disposed of noncontrolling ownership interests in certain companies where we had an existing controlling interest prior to and after the related acquisition or disposal transactions.