Condensed Consolidated Statements of Stockholder Equity (Deficit) (Unaudited) - USD ($) $ in Millions		Total		Cumulative Effect, Period of Adoption, Adjustment	Dun & Bradstreet Corp	Total Stockholder Equity (Deficit)	Total Stockholder Equity (Deficit) Cumulative Effect, Period of Adoption, Adjustment	Total Stockholder Equity (Deficit) Dun & Bradstreet Corp	Common Stock	Common Stock  Dun & Bradstreet Corp	Capital Surplus	Capital Surplus Dun & Bradstreet Corp	(Accumulated Deficit) Retained Earnings	(Accumulated Deficit) Retained Earnings Cumulative Effect, Period of Adoption, Adjustment	(Accumulated Deficit) Retained Earnings Dun & Bradstreet Corp	Treasury Stock	Treasury Stock Dun & Bradstreet Corp	Cumulative Translation Adjustment	Cumulative Translation Adjustment Dun & Bradstreet Corp	Defined Benefit Postretirement Plans	Defined Benefit Postretirement Plans Dun & Bradstreet Corp	Cash Flow Hedging Derivative	Cash Flow Hedging Derivative Dun & Bradstreet Corp	Non-Controlling Interest	Non-Controlling Interest Dun & Bradstreet Corp
Tax benefit (expense) related to pension adjustment		$ (5.5)
Tax benefit of cumulative adjustment for accounting standards update		25.7
Foreign currency translation adjustments, tax expense (benefit)		(2.6)
Derivative financial instruments, tax expense (benefit)		(0.1)
Balance at beginning of period at Dec. 31, 2017				$ (81.1)	$ (811.2)		$ (81.1)	$ (827.3)		$ 0.8		$ 332.0		$ (81.1)	$ 3,176.3		$ (3,319.5)		$ (218.2)		$ (798.7)		$ 0.0		$ 16.1
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)		294.3				$ 288.1							$ 288.1											$ 6.2
Payment to non-controlling interest		(5.5)																						(5.5)
Equity-based compensation plans		10.0				10.0					$ 0.8					$ 9.2
Pension adjustments, net of tax expense (benefit)		(19.6)				(19.6)														$ (19.6)
Dividend declared		(58.3)				(58.3)							(58.3)
Change in cumulative translation adjustment, net of tax expense (benefit)		(18.2)	[1]			(17.3)												$ (17.3)						(0.9)
Derivative financial instruments, net of tax expense (benefit)		(0.3)	[2]			(0.3)																$ (0.3)
Balance at end of period at Dec. 31, 2018		(13.5)			(689.9)	(13.5)		(705.8)		0.8		332.8	(13.5)		3,325.0		(3,310.3)	(235.5)	(235.5)	(818.3)	(818.3)	(0.3)	(0.3)		15.9
Tax benefit (expense) related to pension adjustment		(22.2)
Foreign currency translation adjustments, tax expense (benefit)		0.1
Derivative financial instruments, tax expense (benefit)		(0.1)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)		(74.8)	[3]			(75.6)							(75.6)											0.8
Payment to non-controlling interest		(0.1)																						(0.1)
Equity-based compensation plans		11.7				11.7					11.7
Pension adjustments, net of tax expense (benefit)		65.4				65.4														65.4
Change in cumulative translation adjustment, net of tax expense (benefit)		5.9	[1],[3]			5.7												5.7						0.2
Derivative financial instruments, net of tax expense (benefit)		(0.1)	[2],[3]			(0.1)																(0.1)
Balance at end of period at Feb. 07, 2019		(681.9)				(698.7)			$ 0.8		344.5		3,249.4			(3,310.3)		(229.8)		(752.9)		(0.4)		16.8
Tax benefit (expense) related to pension adjustment		5.4
Foreign currency translation adjustments, tax expense (benefit)		(1.8)
Derivative financial instruments, tax expense (benefit)		(0.4)
Balance at beginning of period at Dec. 31, 2018		(13.5)			$ (689.9)	(13.5)		$ (705.8)		$ 0.8		$ 332.8	(13.5)		$ 3,325.0		$ (3,310.3)	(235.5)	$ (235.5)	(818.3)	$ (818.3)	(0.3)	$ (0.3)		$ 15.9
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)		(553.5)	[3]			(560.0)							(560.0)											6.5
Payment to non-controlling interest		(5.7)																						(5.7)
Take-Private Transaction		2,108.7				2,048.4					2,048.4													60.3
Capital / equity contribution		100.0				100.0					100.0
Equity-based compensation plans		68.0				68.0					68.0
Preferred dividend		(96.1)				(96.1)					(96.1)
Accretion - Series A Preferred Stock		(3.4)				(3.4)					(3.4)
Pension adjustments, net of tax expense (benefit)		(15.8)				(15.8)														(15.8)
Change in cumulative translation adjustment, net of tax expense (benefit)		(9.9)	[1],[3]			(6.6)												(6.6)						(3.3)
Derivative financial instruments, net of tax expense (benefit)		(1.1)	[2],[3]			(1.1)																(1.1)
Balance at end of period at Dec. 31, 2019		1,577.7				1,519.9			0.0		2,116.9		(573.5)			0.0		(6.6)		(15.8)		(1.1)		57.8
Tax benefit (expense) related to pension adjustment		34.8
Foreign currency translation adjustments, tax expense (benefit)		3.0
Derivative financial instruments, tax expense (benefit)		0.2
Conversion of pre-IPO liability classified as equity-based awards to restricted stock units		0.2
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)		(106.5)				(111.5)							(111.5)											5.0
Payment to non-controlling interest		(7.4)																						(7.4)
Issuance of Class A Common Stock in IPO, net of issuance costs		2,248.2				2,248.2					2,248.2
Equity-based compensation plans	[4]	45.3				45.3					45.3
Preferred dividend		(64.1)				(64.1)					(64.1)
Accretion - Series A Preferred Stock		(36.1)				(36.1)					(36.1)
Pension adjustments, net of tax expense (benefit)		(106.5)				(106.5)														(106.5)
Change in cumulative translation adjustment, net of tax expense (benefit)		26.4	[1]			23.3												23.3						3.1
Derivative financial instruments, net of tax expense (benefit)		0.7	[2]			0.7																0.7
Balance at end of period at Dec. 31, 2020		$ 3,577.7				$ 3,519.2			$ 0.0		$ 4,310.2		$ (685.0)			$ 0.0		$ 16.7		$ (122.3)		$ (0.4)		$ 58.5

[1] Tax Expense (Benefit) of $3.0 million, $(1.8) million, less than $0.1 million, and $(2.6) million for the Successor year ended December 31, 2020, for the Successor period from January 1 to December 31, 2019, for the Predecessor period from January 1 to February 7, 2019, and for Predecessor year ended December 31, 2018, respectively.

[2] Tax Expense (Benefit) of $0.2 million, $(0.4) million, $(0.1) million, and $(0.1) million for the Successor year ended December 31, 2020, for the Successor period from January 1 to December 31, 2019, for the Predecessor period from January 1 to February 7, 2019, and for Predecessor year ended December 31, 2018, respectively.

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

[4] Includes $0.2 million related to the conversion of pre-IPO liability classified equity-based awards into restricted stock units.