Consolidated Statements of Comprehensive Loss - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Statement of Comprehensive Income [Abstract]
Net loss	$ (345.3)	$ (791.7)	$ (573.6)
Other comprehensive income (loss):
Foreign currency translation adjustments	13.8	(97.2)	69.5
Defined benefit pension plan adjustments	(0.3)	6.3	(23.8)
Cash flow hedges	(7.8)	(27.5)	(40.1)
Total other comprehensive income (loss)	5.7	(118.4)	5.6
Total other comprehensive loss	(339.6)	(910.1)	(568.0)
Less: Comprehensive income attributable to noncontrolling interests	8.0	6.3	3.8
Total comprehensive loss attributable to NIQ	$ (347.6)	$ (916.4)	$ (571.8)