Common Stock - Common Stock Outstanding (Details) - $ / shares				12 Months Ended
	Dec. 05, 2025	Sep. 09, 2024	Apr. 16, 2024	Dec. 31, 2025	Dec. 31, 2024
Common Stock Outstanding [Roll Forward]
Balance, beginning of period (in shares)				200,174,493	200,000,000
Reclassification (in shares)					0
Initial public offering (in shares)					0
Follow-on public offering (in shares)				0	0
Balance, end of period (in shares)				201,025,964	200,174,493
Common Stock Shares Issued Not Disclosed				Total
Long-Term Incentive Plan
Common Stock Outstanding [Roll Forward]
Shares issued under long-term incentive plans (in shares)				577,459	174,493
Employee Stock Purchase Plan
Common Stock Outstanding [Roll Forward]
Shares issued under long-term incentive plans (in shares)				274,012
Class A
Common Stock Outstanding [Roll Forward]
Balance, beginning of period (in shares)				62,044,493	200,000,000
Reclassification (in shares)					(200,000,000)
Initial public offering (in shares)					38,870,000
Follow-on public offering (in shares)				14,375,000	23,000,000
Balance, end of period (in shares)				77,270,964	62,044,493
Class A \| Long-Term Incentive Plan
Common Stock Outstanding [Roll Forward]
Shares issued under long-term incentive plans (in shares)				577,459	174,493
Class A \| Employee Stock Purchase Plan
Common Stock Outstanding [Roll Forward]
Shares issued under long-term incentive plans (in shares)				274,012
Class A \| IPO
Common Stock Outstanding [Roll Forward]
Shares sold in IPO (in shares)			38,870,000
Price per share for IPO (in dollars per share)			$ 28.00
Class A \| Over-Allotment Option
Common Stock Outstanding [Roll Forward]
Shares sold in IPO (in shares)	1,875,000	3,000,000	5,070,000
Class A \| Follow on Public Offering
Common Stock Outstanding [Roll Forward]
Shares sold in IPO (in shares)	14,375,000	23,000,000
Price per share for IPO (in dollars per share)	$ 78.00	$ 49.00
Class B
Common Stock Outstanding [Roll Forward]
Balance, beginning of period (in shares)				138,130,000	0
Reclassification (in shares)					200,000,000
Initial public offering (in shares)					(38,870,000)
Follow-on public offering (in shares)				(14,375,000)	(23,000,000)
Balance, end of period (in shares)				123,755,000	138,130,000
Class B \| Long-Term Incentive Plan
Common Stock Outstanding [Roll Forward]
Shares issued under long-term incentive plans (in shares)				0	0
Class B \| Employee Stock Purchase Plan
Common Stock Outstanding [Roll Forward]
Shares issued under long-term incentive plans (in shares)				0

UL Solutions Inc. 10-K