Condensed Consolidated Statements of Operations and Comprehensive Income (Loss) (Unaudited) - USD ($) shares in Millions, $ in Millions		3 Months Ended
		Mar. 31, 2021	Mar. 31, 2020
Income Statement [Abstract]
Revenue		$ 504.5	$ 395.7	[1]
Operating expenses		160.9	138.6	[1]
Selling and administrative expenses		179.8	125.1	[1]
Depreciation and amortization		149.7	134.4	[1]
Restructuring charges		5.8	4.8	[2]
Operating costs		496.2	402.9	[1]
Operating income (loss)		8.3	(7.2)	[1]
Interest income		0.1	0.3	[1]
Interest expense		(48.9)	(83.0)	[1]
Other income (expense) - net		6.8	89.3	[1]
Non-operating income (expense) - net		(42.0)	6.6	[1]
Income (loss) before provision (benefit) for income taxes and equity in net income of affiliates		(33.7)	(0.6)	[1]
Less: provision (benefit) for income taxes		(9.8)	(74.2)	[1]
Equity in net income of affiliates		0.6	0.7	[1]
Net income (loss)		(23.3)	74.3	[2]
Less: net (income) loss attributable to the non-controlling interest		(1.7)	(0.4)	[1]
Less: Dividends allocated to preferred stockholders		0.0	(32.0)	[1]
Net income (loss) attributable to Dun & Bradstreet Holdings, Inc.		$ (25.0)	$ 41.9	[1]
Basic earnings (loss) per share of common stock attributable to Dun & Bradstreet Holdings, Inc. (USD per share)		$ (0.06)	$ 0.13	[1]
Diluted earnings (loss) per share of common stock attributable to Dun & Bradstreet Holdings, Inc. (USD per share)		$ (0.06)	$ 0.13	[1]
Weighted average number of shares outstanding - basic (shares)		428.5	314.5	[1]
Weighted average number of shares outstanding - diluted (shares)		428.5	314.5	[1]
Other comprehensive income (loss), net of income taxes:
Net income (loss)		$ (23.3)	$ 74.3	[2]
Foreign currency translation adjustments, net of tax	[3]	(49.3)	(25.6)	[1]
Defined benefit pension plans:
Prior service credit (cost), net of tax expense (benefit)	[4]	0.4	(0.1)	[1]
Derivative financial instrument, net of tax expense (benefit)	[5]	1.8	(1.0)	[1]
Total other comprehensive income (loss), net of tax		(47.1)	(26.7)	[1]
Comprehensive income (loss), net of tax		(70.4)	47.6	[1]
Less: comprehensive (income) loss attributable to the non-controlling interest		(2.4)	0.9	[1]
Comprehensive income (loss) attributable to Dun & Bradstreet Holdings, Inc.		(72.8)	48.5	[1]
Income Statement - Parenthetical [Abstract]
Foreign currency translation adjustments, tax expense (benefit)		1.1	(0.2)
Prior service credit (cost), tax benefit		0.1	(0.1)
Derivative financial instrument, tax expense (benefit)		$ (0.1)	$ (0.3)

[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 $1.1 million and $(0.2) million for the three months ended March 31, 2021 and 2020, respectively.

[4] Tax Expense (Benefit) of $0.1 million and less than $(0.1) million for the three months ended March 31, 2021 and 2020, respectively.

[5] Tax Expense (Benefit) of $(0.1) million and $(0.3) million for the three months ended March 31, 2021 and 2020, respectively.