Condensed Consolidated Statements of Operations and Comprehensive Income (Loss) - USD ($) shares in Millions, $ in Millions		3 Months Ended			6 Months Ended
		Jun. 30, 2021	Jun. 30, 2020		Jun. 30, 2021	Jun. 30, 2020
Income Statement [Abstract]
Revenue		$ 520.9	$ 418.7	[1]	$ 1,025.4	$ 814.4	[1]
Operating expenses		167.3	136.8	[1]	328.2	275.4	[1]
Selling and administrative expenses		164.3	144.4	[1]	344.1	269.5	[1]
Depreciation and amortization		152.3	132.7	[1]	302.0	267.1	[1]
Restructuring charges		10.1	7.1	[1]	15.9	11.9	[2]
Operating costs		494.0	421.0	[1]	990.2	823.9	[1]
Operating income (loss)		26.9	(2.3)	[1]	35.2	(9.5)	[1]
Interest income		0.2	0.2	[1]	0.3	0.5	[1]
Interest expense		(48.0)	(78.0)	[1]	(96.9)	(161.0)	[1]
Other income (expense) - net		12.4	(122.9)	[1]	19.2	(33.6)	[1]
Non-operating income (expense) - net		(35.4)	(200.7)	[1]	(77.4)	(194.1)	[1]
Income (loss) before provision (benefit) for income taxes and equity in net income of affiliates		(8.5)	(203.0)	[1]	(42.2)	(203.6)	[1]
Less: provision (benefit) for income taxes		43.0	(27.7)	[1]	33.2	(101.9)	[1]
Equity in net income of affiliates		0.7	0.6	[1]	1.3	1.3	[1]
Net income (loss)		(50.8)	(174.7)	[1]	(74.1)	(100.4)	[1]
Less: net (income) loss attributable to the non-controlling interest		(0.9)	(1.2)	[1]	(2.6)	(1.6)	[1]
Less: Dividends allocated to preferred stockholders		0.0	(32.1)	[1]	0.0	(64.1)	[1]
Net income (loss) attributable to Dun & Bradstreet Holdings, Inc., Basic		(51.7)	(208.0)	[1]	(76.7)	(166.1)	[1]
Net income (loss) attributable to Dun & Bradstreet Holdings, Inc., diluted		$ (51.7)	$ (208.0)		$ (76.7)	$ (166.1)
Basic earnings (loss) per share of common stock attributable to Dun & Bradstreet Holdings, Inc. (USD per share)		$ (0.12)	$ (0.66)	[1]	$ (0.18)	$ (0.53)	[1]
Diluted earnings (loss) per share of common stock attributable to Dun & Bradstreet Holdings, Inc. (USD per share)		$ (0.12)	$ (0.66)	[1]	$ (0.18)	$ (0.53)	[1]
Weighted average number of shares outstanding - basic (shares)		428.9	314.5	[1]	428.7	314.5	[1]
Weighted average number of shares outstanding - diluted (shares)		428.9	314.5	[1]	428.7	314.5	[1]
Other comprehensive income (loss), net of income taxes:
Net income (loss)		$ (50.8)	$ (174.7)	[1]	$ (74.1)	$ (100.4)	[1]
Foreign currency translation adjustments, net of tax	[3]	16.4	3.5	[1]	(32.9)	(22.1)	[1]
Defined benefit pension plans:
Prior service credit (cost), net of tax expense (benefit)	[4]	(0.1)	0.0	[1]	(0.1)	(0.1)	[1]
Net actuarial gain (loss), net of tax expense (benefit) (4)	[5]	0.5	0.0	[1]	0.9	0.0	[1]
Derivative financial instrument, net of tax expense (benefit)	[6]	(1.0)	0.5	[1]	0.8	(0.5)	[1]
Total other comprehensive income (loss), net of tax		15.8	4.0	[1]	(31.3)	(22.7)	[1]
Comprehensive income (loss), net of tax		(35.0)	(170.7)	[1]	(105.4)	(123.1)	[1]
Less: comprehensive (income) loss attributable to the non-controlling interest		(1.8)	(1.4)	[1]	(4.2)	(0.5)	[1]
Comprehensive income (loss) attributable to Dun & Bradstreet Holdings, Inc.		$ (36.8)	$ (172.1)	[1]	$ (109.6)	$ (123.6)	[1]

[1] See discussion in Note 1 - Basis of Presentation for further detail regarding the elimination of the International lag reporting.

[2] See discussion in Note 1 - Basis of Presentation for further detail regarding the elimination of the International lag reporting.

[3] Tax Expense (Benefit) of $1.9 million and $(0.7) million for the three months ended June 30, 2021 and 2020, respectively. Tax Expense (Benefit) of $3.0 million and $(0.9) million for the six months ended June 30, 2021 and 2020, respectively.

[4] Tax Expense (Benefit) of less than $(0.1) million for the three months ended June 30, 2021. Tax Expense (Benefit) of $(0.1) million for the six months ended June 30, 2021.

[5] Tax Expense (Benefit) of less than $0.1 million for the three months ended June 30, 2021. Tax Expense (Benefit) of $0.2 million for the six months ended June 30, 2021.

[6] Tax Expense (Benefit) of $0.4 million and $0.1 million for the three months ended June 30, 2021 and 2020, respectively. Tax Expense (Benefit) of $0.3 million and $(0.2) million for the six months ended June 30, 2021 and 2020, respectively.