Quarterly Financial Data (Unaudited) (Details) - USD ($) $ 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
Business Acquisition [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]
Net income (loss)	(74.8)	[1]	(10.0)	18.2	(50.8)	(23.3)	3.1	(14.3)	(174.7)	74.3	(65.9)	(111.6)	[1],[2]	(553.7)	[1],[2]
Net income (loss) attributable to non-controlling interest	(0.8)	[1]	(1.6)	(1.6)	(0.9)	(1.7)	(1.3)	(2.0)	(1.2)	(0.4)	(5.8)	(4.9)	[1]	(6.4)	[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)
Contract with customer, liability, purchase accounting adjustments												(21.1)		(138.9)
Total compensation expense for stock options granted	11.7										33.3	45.1		11.7
Redemption premium			29.5
Write off of debt discount and issuance costs			$ 12.5
Other nonoperating expense related to partial debt redemption	0.0							$ 25.5	41.3		29.5	50.1		0.0
Gain (loss) on embedded derivative	0.0								(102.6)	69.8	0.0	(32.8)	[2]	(172.4)	[2]
Take-Private Acquisition, Dun & Bradstreet
Business Acquisition [Line Items]
Revenue														1,413.9		$ 0.0
Contract with customer, liability, purchase accounting adjustments										$ 17.4
Stock options
Business Acquisition [Line Items]
Total compensation expense for stock options granted	$ 0.0								$ 20.0		$ 3.0	$ 23.0		$ 0.0

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

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