Acquisitions - Purchase Price Allocation (Details) - USD ($) $ in Millions				12 Months Ended
	Nov. 15, 2021	Nov. 05, 2021	Jan. 08, 2021	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Initial purchase price allocation:
Goodwill				$ 3,445.8	$ 3,431.3	$ 3,493.3
Eyeota Holdings Pte Ltd
Initial purchase price allocation:
Cash					7.1
Accounts receivable					9.3
Other					0.5
Total current assets					16.9
Goodwill					138.5
Total assets acquired					190.4
Deferred tax liability					5.9
Other liabilities					12.1
Total liabilities assumed					18.0
Total consideration					172.4
NetWise Data, LLC
Initial purchase price allocation:
Cash					2.6
Accounts receivable					2.6
Other					0.4
Total current assets					5.6
Goodwill					2.2
Total assets acquired					45.5
Deferred tax liability					74.6
Other liabilities					4.4
Total liabilities assumed					70.2
Bisnode Business Information Group AB
Initial purchase price allocation:
Cash						29.9
Accounts receivable						61.0
Other						13.1
Total current assets						104.0
Property, plant & equipment						3.5
Goodwill						495.4
Right of use asset						27.4
Other						2.9
Total assets acquired						1,186.2
Accounts payable						17.5
Deferred revenue						80.6
Accrued payroll						20.7
Accrued income tax and other tax liabilities						17.1
Short-term lease liability						8.6
Other current liabilities						23.7
Total current liabilities						168.2
Long-term pension and postretirement obligations						65.4
Deferred tax liability						127.8
Long-term lease liability						18.2
Other liabilities						0.8
Total liabilities assumed						380.4
Total consideration						805.8
Reacquired right
Business Acquisition [Line Items]
Weighted average amortization period (in years)				15 years
Reacquired right | Bisnode Business Information Group AB
Business Acquisition [Line Items]
Weighted average amortization period (in years)			15 years
Initial purchase price allocation:
Intangible assets:						270.0
Database
Business Acquisition [Line Items]
Weighted average amortization period (in years)				17 years
Database | NetWise Data, LLC
Business Acquisition [Line Items]
Weighted average amortization period (in years)	3 years
Database | Bisnode Business Information Group AB
Business Acquisition [Line Items]
Weighted average amortization period (in years)			12 years
Initial purchase price allocation:
Intangible assets:						111.0
Customer Relationships
Business Acquisition [Line Items]
Weighted average amortization period (in years)				17 years
Customer Relationships | Eyeota Holdings Pte Ltd
Business Acquisition [Line Items]
Weighted average amortization period (in years)		14 years
Initial purchase price allocation:
Intangible assets:					20.0
Customer Relationships | NetWise Data, LLC
Business Acquisition [Line Items]
Weighted average amortization period (in years)	15 years
Initial purchase price allocation:
Intangible assets:					19.8
Customer Relationships | Bisnode Business Information Group AB
Business Acquisition [Line Items]
Weighted average amortization period (in years)			10 years
Initial purchase price allocation:
Intangible assets:						108.0
Technology-Based Intangible Assets
Business Acquisition [Line Items]
Weighted average amortization period (in years)				10 years
Technology-Based Intangible Assets | Eyeota Holdings Pte Ltd
Business Acquisition [Line Items]
Weighted average amortization period (in years)		5 years
Initial purchase price allocation:
Intangible assets:					14.0
Technology-Based Intangible Assets | NetWise Data, LLC
Business Acquisition [Line Items]
Weighted average amortization period (in years)	5 years
Initial purchase price allocation:
Intangible assets:					1.3
Technology-Based Intangible Assets | Bisnode Business Information Group AB
Business Acquisition [Line Items]
Weighted average amortization period (in years)			14 years
Initial purchase price allocation:
Intangible assets:						$ 64.0
Trademark
Business Acquisition [Line Items]
Weighted average amortization period (in years)				2 years
Trademark | Eyeota Holdings Pte Ltd
Business Acquisition [Line Items]
Weighted average amortization period (in years)		2 years
Initial purchase price allocation:
Intangible assets:					1.0
Trademark | NetWise Data, LLC
Business Acquisition [Line Items]
Weighted average amortization period (in years)	2 years
Initial purchase price allocation:
Intangible assets:					$ 0.2