Acquisitions and Divestitures - Acquisitions (Narrative) (Details) $ in Millions						12 Months Ended
	Sep. 09, 2024 USD ($) employee	Dec. 20, 2023 USD ($) employee	Sep. 01, 2023 USD ($) employee	Apr. 04, 2023 USD ($) employee	Jan. 31, 2023 USD ($) employee	Dec. 31, 2024 USD ($)	Dec. 31, 2023 USD ($) acquisition	Dec. 31, 2022 USD ($)	Nov. 01, 2023 employee	Sep. 29, 2023 employee
Business Acquisition [Line Items]
Cash paid for acquisitions, net of cash acquired						$ 167.4	$ 638.8	$ 453.7
Cash acquired from acquisition						8.9	30.0	19.4
Acquisition-related charges						13.0	$ 31.8	14.8
Number of acquisitions completed | acquisition							6
Goodwill						$ 1,383.3	$ 1,369.6	$ 1,098.3
CGI Inc.
Business Acquisition [Line Items]
Number of employees | employee	130
Lagersmit
Business Acquisition [Line Items]
Number of employees | employee		90
Des-Case
Business Acquisition [Line Items]
Number of employees | employee			120
Nadella
Business Acquisition [Line Items]
Number of employees | employee				450
iMECH
Business Acquisition [Line Items]
Number of employees | employee									70
Rosa Sistemi S.p.A
Business Acquisition [Line Items]
Number of employees | employee										65
ARB
Business Acquisition [Line Items]
Number of employees | employee					190
CGI Inc.
Business Acquisition [Line Items]
Percentage of voting interests acquired	100.00%
Cash paid for acquisitions, net of cash acquired	$ 167.1
Cash acquired from acquisition	8.9
Acquisition-related charges	$ 2.0
Lagersmit
Business Acquisition [Line Items]
Percentage of voting interests acquired		100.00%
Cash paid for acquisitions, net of cash acquired		$ 128.2
Cash acquired from acquisition		$ 6.5
Goodwill							59.1
Intangible assets acquired							71.9
Des-Case
Business Acquisition [Line Items]
Percentage of voting interests acquired			100.00%
Cash paid for acquisitions, net of cash acquired			$ 123.2
Cash acquired from acquisition			$ 1.8
Goodwill							78.7
Intangible assets acquired							45.1
Nadella
Business Acquisition [Line Items]
Percentage of voting interests acquired				100.00%
Cash paid for acquisitions, net of cash acquired				$ 293.5
Cash acquired from acquisition				$ 21.0
Goodwill							129.0
Intangible assets acquired							158.9
iMECH
Business Acquisition [Line Items]
Percentage of voting interests acquired									100.00%
Rosa Sistemi S.p.A
Business Acquisition [Line Items]
Percentage of voting interests acquired										100.00%
ARB
Business Acquisition [Line Items]
Cash paid for acquisitions, net of cash acquired					$ 95.7
Cash acquired from acquisition					$ 1.4
2023 Acquisitions
Business Acquisition [Line Items]
Cash paid for acquisitions, net of cash acquired							638.8
Transaction costs							6.7
Goodwill							292.0
Intangible assets acquired							$ 299.5