Basis of Presentation and Description of Business - Changes to Annual Results: Income Statement (Details) - USD ($) $ / shares in Units, $ in Millions	1 Months Ended		3 Months Ended								12 Months Ended
	Feb. 07, 2019		Dec. 31, 2021	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2021	Dec. 31, 2020		Dec. 31, 2019		Dec. 31, 2018
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Revenue	$ 178.7	[1]	$ 598.3	$ 541.9	$ 520.9	$ 504.5	$ 479.9	$ 444.4	$ 418.7	$ 395.7	$ 2,165.6	$ 1,738.7	[1]	$ 1,439.0	[1]	$ 1,716.4
Operating income (loss)	(11.6)	[1]	60.9	49.5	26.9	8.3	19.6	45.5	(2.3)	(7.2)	145.6	55.6	[1]	(221.7)	[1]
Income (loss) before provision (benefit) for income taxes and equity in net income of affiliates	(102.8)	[1]									(45.2)	(226.4)	[1]	(676.2)	[1]
Provision (benefit) for income taxes	(27.5)	[1]									23.4	(112.4)	[1]	(118.3)	[1]
Net income (loss) attributable to Dun & Bradstreet Holdings, Inc., basic	$ (75.6)		$ (11.6)	$ 16.6	$ (51.7)	$ (25.0)	$ 1.8	$ (16.3)	$ (208.0)	$ 41.9	(71.7)	(180.6)	[1]	(674.1)
Net income (loss) attributable to Dun & Bradstreet Holdings, Inc., diluted											$ (71.7)	$ (180.6)	[1]	$ (674.1)
Basic earnings (loss) per share of common stock attributable to Dun & Bradstreet Holdings, Inc.	$ (2.04)	[1]									$ (0.17)	$ (0.49)	[1]	$ (2.14)	[1]
Diluted earnings (loss) per share of common stock attributable to Dun & Bradstreet Holdings, Inc.	$ (2.04)	[1]									$ (0.17)	$ (0.49)	[1]	$ (2.14)	[1]
As Reported
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Revenue												$ 1,738.1		$ 1,413.9
Operating income (loss)												63.0		(220.0)
Income (loss) before provision (benefit) for income taxes and equity in net income of affiliates												(219.3)		(675.9)
Provision (benefit) for income taxes												(110.5)		(118.2)
Net income (loss) attributable to Dun & Bradstreet Holdings, Inc., basic												(175.6)		(674.0)
Net income (loss) attributable to Dun & Bradstreet Holdings, Inc., diluted												$ (175.6)		$ (674.0)
Basic earnings (loss) per share of common stock attributable to Dun & Bradstreet Holdings, Inc.												$ (0.48)		$ (2.14)
Diluted earnings (loss) per share of common stock attributable to Dun & Bradstreet Holdings, Inc.												$ (0.48)		$ (2.14)
Increase (Decrease)
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Revenue												$ 0.6		$ 25.1
Operating income (loss)												(7.4)		(1.7)
Income (loss) before provision (benefit) for income taxes and equity in net income of affiliates												(7.1)		(0.3)
Provision (benefit) for income taxes												(1.9)		(0.1)
Net income (loss) attributable to Dun & Bradstreet Holdings, Inc., basic												(5.0)		(0.1)
Net income (loss) attributable to Dun & Bradstreet Holdings, Inc., diluted												$ (5.0)		$ (0.1)
Basic earnings (loss) per share of common stock attributable to Dun & Bradstreet Holdings, Inc.												$ (0.01)		$ 0
Diluted earnings (loss) per share of common stock attributable to Dun & Bradstreet Holdings, Inc.												$ (0.01)		$ 0

[1] See Note 1 Basis of Presentation and Description of Business for further detail regarding the elimination of the International lag reporting.