Consolidated Statements of Stockholders' Equity (Deficit) - USD ($) $ in Millions		Total		Total stockholders' equity (deficit)	Common stock	Capital surplus	(Accumulated deficit) retained earnings	Treasury stock	Cumulative translation adjustment	Defined benefit postretirement plans	Cash flow hedging derivative	Non-controlling interest
Balance at beginning of period at Dec. 31, 2020		$ 3,583.9		$ 3,525.6	$ 0.0	$ 4,310.2	$ (690.1)	$ 0.0	$ 26.2	$ (120.3)	$ (0.4)	$ 58.3
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)		(65.9)		(71.7)			(71.7)					5.8
Shares issued for Bisnode acquisition		158.9		158.9		158.9
Equity-based compensation plans		31.0		31.0		31.3		(0.3)
Pension adjustments, net of tax benefit		108.4		108.4						108.4
Change in cumulative translation adjustment, net of tax expense		(76.6)	[1]	(78.8)					(78.8)			2.2
Net investment hedge derivative, net of tax benefit of	[2]	0.0
Cash flow hedge derivative, net of tax expense		7.8	[3]	7.8							7.8
Payment to non-controlling interest		(2.2)										(2.2)
Balance at end of period at Dec. 31, 2021		3,745.3		3,681.2	0.0	4,500.4	(761.8)	(0.3)	(52.6)	(11.9)	7.4	64.1
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)		4.1		(2.3)			(2.3)					6.4
Purchase of non-controlling interest	[4]	(116.2)		(73.8)		(73.8)						(42.4)
Reclassification of cumulative translation adjustment related to the purchase of non-controlling interest		0.0		(3.8)					(3.8)			3.8
Equity-based compensation plans		60.7		60.7		60.7
Dividends declared	[5]	(43.6)		(43.6)		(43.6)
Pension adjustments, net of tax benefit		(46.2)		(46.2)						(46.2)
Change in cumulative translation adjustment, net of tax expense		(124.6)	[1]	(115.9)					(115.9)			(8.7)
Net investment hedge derivative, net of tax benefit of		2.0	[2]	2.0					2.0
Cash flow hedge derivative, net of tax expense		41.0	[3]	41.0							41.0
Payment to non-controlling interest		(14.1)										(14.1)
Balance at end of period at Dec. 31, 2022		3,508.4		3,499.3	0.0	4,443.7	(764.1)	(0.3)	(170.3)	(58.1)	48.4	9.1
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)		(43.7)		(47.0)			(47.0)					3.3
Equity-based compensation plans		73.0		73.0		73.0
Dividends declared	[5]	(87.5)		(87.5)		(87.5)
Pension adjustments, net of tax benefit		(4.1)		(4.1)						(4.1)
Change in cumulative translation adjustment, net of tax expense		29.9	[1]	29.8					29.8			0.1
Net investment hedge derivative, net of tax benefit of		(12.5)	[2]	(12.5)					(12.5)
Cash flow hedge derivative, net of tax expense		(31.9)	[3]	(31.9)							(31.9)
Balance at end of period at Dec. 31, 2023		$ 3,431.6		$ 3,419.1	$ 0.0	$ 4,429.2	$ (811.1)	$ (0.3)	$ (153.0)	$ (62.2)	$ 16.5	$ 12.5

[1] Tax Expense (Benefit) of $7.9 million, $(9.9) million and $(1.6) million, for the years ended December 31, 2023, 2022 and 2021, respectively.

[2] Tax Expense (Benefit) of $(4.5) million and $0.9 million for the years ended December 31, 2023 and 2022, respectively.

[3] Tax Expense (Benefit) of $(11.5) million, $14.6 million and $2.8 million, for the years ended December 31, 2023, 2022 and 2021, respectively.

[4] See Note 17 "Supplemental Financial Data" for further discussion.

[5] See Note 13 "Earnings (Loss) Per Share" for further discussion.