Condensed Consolidated Statements of Equity (Unaudited) - USD ($) $ in Millions	Total	Total NIQ Shareholders’ Equity	Ordinary Shares	Preferred Shares	Euro Deferred Shares	Paid-In Capital	Accumulated Deficit	Accumulated Other Comprehensive Loss	Noncontrolling Interests
Beginning balance (in shares) at Dec. 31, 2024			245,000,000		0
Beginning balance (in shares) at Dec. 31, 2024				0
Beginning balance at Dec. 31, 2024	$ 298.6	$ 59.7	$ 0.0	$ 0.0	$ 0.0	$ 1,946.1	$ (1,848.7)	$ (37.7)	$ 238.9
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income	(117.9)	(119.8)					(119.8)		1.9
Other comprehensive income (loss)	(11.2)	(11.2)						(11.2)
Share-based compensation	1.3	1.3				1.3
Cash dividends paid to noncontrolling interests	(3.0)								(3.0)
Ending balance (in shares) at Mar. 31, 2025			245,000,000		0
Ending balance (in shares) at Mar. 31, 2025				0
Ending balance at Mar. 31, 2025	$ 167.8	(70.0)	$ 0.0	$ 0.0	$ 0.0	1,947.4	(1,968.5)	(48.9)	237.8
Beginning balance (in shares) at Dec. 31, 2025	295,000,000		295,000,000		25,000
Beginning balance (in shares) at Dec. 31, 2025	0			0
Beginning balance at Dec. 31, 2025	$ 1,225.6	988.4	$ 0.0	$ 0.0	$ 0.0	3,222.4	(2,202.0)	(32.0)	237.2
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income	(88.7)	(90.1)					(90.1)		1.4
Other comprehensive income (loss)	6.8	6.8						6.8
Vesting of restricted stock units (in shares)			115,271
Share-based compensation	11.5	11.5				11.5
Withholding tax paid upon equity award vesting	(0.4)	(0.4)				(0.4)
Other	$ (0.3)	(0.3)				(0.3)
Ending balance (in shares) at Mar. 31, 2026	295,115,271		295,115,271		25,000
Ending balance (in shares) at Mar. 31, 2026	0			0
Ending balance at Mar. 31, 2026	$ 1,154.5	$ 915.9	$ 0.0	$ 0.0	$ 0.0	$ 3,233.2	$ (2,292.1)	$ (25.2)	$ 238.6