Acquisitions - Purchase Price Allocation (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 01, 2021
Business Acquisition [Line Items]
Goodwill	$ 4,413.4	$ 4,342.7	$ 4,382.9
Sirius Computer Solutions, Inc.
Business Acquisition [Line Items]
Cash and cash equivalents				$ 52.8
Accounts receivable				634.1
Intangible assets, net				1,164.0
Goodwill				1,566.6
Other assets				438.1
Total assets acquired				3,855.6
Accounts payable-trade				633.8
Debt				170.1
Deferred tax liabilities				207.0
Other liabilities				389.7
Total liabilities assumed				1,400.6
Total purchase price				$ 2,455.0