Segment Reporting (Income From Operations and Total Assets) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Reconciliation of Income From Operations from Segments to Consolidated
Income from operations	$ 273.6	$ 387.3
Amortization of intangibles	(13.9)	(14.8)
Restructuring expenses	(1.0)	(1.4)
Reconciliation of Assets from Segment to Consolidated
Assets	13,459.9		$ 11,421.2
Cash and cash equivalents	2,455.8		595.5
Investments in affiliates	520.5		512.7
Intangible assets, net	291.6		308.8
Goodwill	1,325.8		1,333.4
Operating Segments
Reconciliation of Income From Operations from Segments to Consolidated
Income from operations	349.5	459.1
Reconciliation of Assets from Segment to Consolidated
Assets	7,400.0		7,170.7
Segment Reconciling Items
Reconciliation of Income From Operations from Segments to Consolidated
Corporate expenses	(53.0)	(42.1)
Amortization of intangibles	(13.9)	(14.8)
Stock compensation expense	(8.0)	(13.5)
Restructuring expenses	(1.0)	$ (1.4)
Reconciliation of Assets from Segment to Consolidated
Cash and cash equivalents	2,455.8		595.5
Investments in affiliates	520.5		512.7
Deferred tax assets, other current and noncurrent assets	1,466.2		1,500.1
Intangible assets, net	291.6		308.8
Goodwill	$ 1,325.8		$ 1,333.4