Condensed Consolidated Statements of Operations and Comprehensive Income (Loss) (Unaudited) - USD ($) shares in Millions, $ in Millions		1 Months Ended	3 Months Ended		6 Months Ended
		Feb. 07, 2019	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Income Statement [Abstract]
Revenue	[1]	$ 178.7	$ 420.6	$ 398.9	$ 815.9	$ 573.0
Operating expenses	[1]	56.7	139.2	127.8	278.1	192.2
Selling and administrative expenses	[1]	122.4	143.4	126.0	269.3	339.6
Depreciation and amortization	[1]	11.1	132.6	136.8	266.9	217.3
Restructuring charge	[1]	0.1	6.8	17.4	11.3	35.9
Operating costs	[1]	190.3	422.0	408.0	825.6	785.0
Operating income (loss)	[1]	(11.6)	(1.4)	(9.1)	(9.7)	(212.0)
Interest income	[1]	0.3	0.2	0.6	0.5	1.6
Interest expense	[1]	(5.5)	(78.0)	(86.0)	(161.0)	(135.0)
Other income (expense) - net	[1]	(86.0)	(122.7)	8.1	(32.7)	12.3
Non-operating income (expense) - net	[1]	(91.2)	(200.5)	(77.3)	(193.2)	(121.1)
Income (loss) before provision (benefit) for income taxes and equity in net income of affiliates	[1]	(102.8)	(201.9)	(86.4)	(202.9)	(333.1)
Less: provision (benefit) for income taxes	[1]	(27.5)	(27.5)	(23.1)	(101.8)	(60.1)
Equity in net income of affiliates	[1]	0.5	0.6	2.8	1.2	2.9
Net income (loss)	[1]	(74.8)	(173.8)	(60.5)	(99.9)	(270.1)
Less: net (income) loss attributable to the non-controlling interest	[1]	(0.8)	(1.2)	(1.5)	(1.6)	(1.9)
Less: Dividends allocated to preferred stockholders	[1]	0.0	(32.1)	(32.0)	(64.1)	(49.9)
Net income (loss) attributable to Dun & Bradstreet Holdings, Inc. (Successor) / The Dun & Bradstreet Corporation (Predecessor)	[1]	$ (75.6)	$ (207.1)	$ (94.0)	$ (165.6)	$ (321.9)
Basic earnings (loss) per share of common stock:
Net income (loss) attributable to Dun & Bradstreet Holdings, Inc. (Successor) / The Dun & Bradstreet Corporation (Predecessor)	[1]	$ (2.04)	$ (0.66)	$ (0.30)	$ (0.53)	$ (1.02)
Diluted earnings (loss) per share of common stock:
Net income (loss) attributable to Dun & Bradstreet Holdings, Inc. (Successor) / The Dun & Bradstreet Corporation (Predecessor)	[1]	$ (2.04)	$ (0.66)	$ (0.30)	$ (0.53)	$ (1.02)
Weighted average number of shares outstanding-basic	[1]	37.2	314.5	314.5	314.5	314.5
Weighted average number of shares outstanding-diluted	[1]	37.2	314.5	314.5	314.5	314.5
Other comprehensive income (loss), net of income taxes:
Net income (loss)	[1]	$ (74.8)	$ (173.8)	$ (60.5)	$ (99.9)	$ (270.1)
Foreign currency translation adjustments, net of tax	[1],[2]	5.9	(13.3)	(16.2)	(14.9)	(16.9)
Defined benefit pension plans:
Prior service credit (cost), net of tax expense (benefit)	[1],[3]	(0.1)	0.0	0.0	(0.1)	0.0
Net actuarial gain (loss), net of tax expense (benefit)	[1],[4]	65.5	0.0	0.0	0.0	0.0
Derivative financial instrument, net of tax expense (benefit)	[1],[5]	(0.1)	0.4	(1.2)	(0.5)	(1.6)
Total other comprehensive income (loss), net of tax	[1]	71.2	(12.9)	(17.4)	(15.5)	(18.5)
Comprehensive income (loss), net of tax	[1]	(3.6)	(186.7)	(77.9)	(115.4)	(288.6)
Less: comprehensive loss (income) attributable to the non-controlling interest	[1]	(1.0)	0.1	(1.3)	(0.4)	(1.8)
Comprehensive income (loss) attributable to Dun & Bradstreet Holdings, Inc. (Successor) / The Dun & Bradstreet Corporation (Predecessor)	[1]	$ (4.6)	$ (186.6)	$ (79.2)	$ (115.8)	$ (290.4)

[1] See Note 1 "Basis of Presentation" for further discussion.

[2] Tax Expense (Benefit) of $(0.7) million, $$(1.9) million, $(0.9) million, $$(0.9) million, and less than $0.1 million for the Successor three months ended June 30, 2020 and 2019, for the Successor six months ended June 30, 2020, for the Successor period from January 1 to June 30, 2019, and for the Predecessor period from January 1 to February 7, 2019, respectively.

[3] Tax Expense (Benefit) of less than $(0.1) million for the Successor six months ended June 30, 2020.

[4] Tax Expense (Benefit) of $22.2 million for the Predecessor period from January 1 to February 7, 2019.

[5] Tax Expense (Benefit) of $0.1 million, $(0.4) million, $(0.2) million, $(0.5) million, and $(0.1) million for the Successor three months ended June 30, 2020 and 2019, for the Successor six months ended June 30, 2020, for the Successor period from January 1 to June 30, 2019, and for the Predecessor period from January 1 to February 7, 2019, respectively.