Consolidated Statements of Operations - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Income Statement [Abstract]
Revenues	$ 4,198.4	$ 3,972.6	$ 3,341.3
Operating expenses:
Cost of revenues (excluding depreciation and amortization shown separately below)	1,862.1	1,771.6	1,511.5
Selling, general and administrative expenses	1,597.7	1,601.4	1,449.4
Depreciation and amortization	632.5	596.7	460.9
Impairment of long-lived assets	1.1	31.1	9.0
Restructuring, net	44.0	98.5	34.6
Other operating income, net	(24.4)	(26.9)	(15.4)
Total operating expenses	4,113.0	4,072.4	3,450.0
Operating income (loss)	85.4	(99.8)	(108.7)
Interest expense, net	(317.6)	(410.6)	(299.5)
Foreign currency exchange gain (loss), net	78.2	(34.2)	4.6
Nonoperating expense, net	(55.8)	(145.9)	(109.2)
Loss from continuing operations before income taxes	(209.8)	(690.5)	(512.8)
Income tax expense from continuing operations	(135.5)	(113.7)	(51.8)
Loss from continuing operations	(345.3)	(804.2)	(564.6)
Discontinued operations (Note 4)
Income from discontinued operations before income taxes	0.0	12.5	2.6
Income tax expense from discontinued operations	0.0	0.0	(11.6)
Income (loss) from discontinued operations	0.0	12.5	(9.0)
Net loss	(345.3)	(791.7)	(573.6)
Less: Net income attributable to noncontrolling interests	8.0	6.3	3.8
Net loss attributable to NIQ	$ (353.3)	$ (798.0)	$ (577.4)
Basic and diluted earnings per share from:
Loss attributable to NIQ, basic (in dollars per share)	$ (1.32)	$ (3.31)	$ (2.32)
Loss attributable to NIQ, diluted (in dollars per share)	(1.32)	(3.31)	(2.32)
Income (loss) from discontinued operations, basic (in dollars per share)	0	0.05	(0.03)
Income (loss) from discontinued operations, diluted (in dollars per share)	0	0.05	(0.03)
Net loss attributable to NIQ, basic (in dollars per share)	(1.32)	(3.26)	(2.35)
Net loss attributable to NIQ, diluted (in dollars per share)	$ (1.32)	$ (3.26)	$ (2.35)
Weighted average basic NIQ ordinary shares outstanding (in shares)	266,917,808	245,000,000	245,000,000
Weighted average diluted NIQ ordinary shares outstanding (in shares)	266,917,808	245,000,000	245,000,000