Goodwill and Identifiable Assets (Goodwill) (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
Mar. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Goodwill [Roll Forward]
Gross goodwill	$ 1,893.5	$ 1,891.9	$ 1,569.5
Goodwill, Purchase Accounting Adjustments	1.1	(8.1)
Translation adjustment	0.5	(1.4)
Commercial Business
Goodwill [Roll Forward]
Gross goodwill	1,075.2	1,074.7	829.3
Goodwill, Purchase Accounting Adjustments	0.0	0.4
Translation adjustment	0.5	(1.4)
Federal Government Business
Goodwill [Roll Forward]
Gross goodwill	818.3	817.2	$ 740.2
Goodwill, Purchase Accounting Adjustments	1.1	(8.5)
Translation adjustment	$ 0.0	0.0
2022 Acquisitions
Goodwill [Roll Forward]
Goodwill, Acquired During Period		331.9
Business Acquisition, Goodwill, Expected Tax Deductible Amount		250.7
2022 Acquisitions \| Commercial Business
Goodwill [Roll Forward]
Goodwill, Acquired During Period		246.4
2022 Acquisitions \| Federal Government Business
Goodwill [Roll Forward]
Goodwill, Acquired During Period		$ 85.5

The amount of goodwill arising from a business combination that is expected to be deductible for tax purposes.

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Amount of increase in asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized resulting from a business combination.

+ References

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Amount of foreign currency translation gain (loss) which increases (decreases) an asset representing future economic benefits from other assets acquired in a business combination that are not individually identified and separately recognized.

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Amount before accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References

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Amount of increase (decrease) from adjustments after acquisition date under purchase accounting of an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References

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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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