Subsequent Events (Details) - USD ($)				3 Months Ended
	May 01, 2024	Apr. 16, 2024	Apr. 01, 2024	Jun. 30, 2024	Mar. 31, 2024	Mar. 31, 2023	Apr. 11, 2024	Dec. 31, 2023
Cash-settled Stock Appreciation Rights
Subsequent Event [Line Items]
Remaining outstanding shares (in shares)					3,452,120			3,452,120
Pre-tax compensation expense					$ (1,000,000)	$ 10,000,000
Subsequent Event | Forecast
Subsequent Event [Line Items]
Reduction of deferred income tax assets				$ 5,000,000
Increase in income taxes from changes to previously deductible expenses				5,000,000
Subsequent Event | UL Standards & Engagement Liabrary Access | UL Solutions
Subsequent Event [Line Items]
Ownership percentage		80.60%
Voting power		97.60%
Subsequent Event | Payments Testing Business | Disposal Group, Disposed of by Sale, Not Discontinued Operations
Subsequent Event [Line Items]
Proceeds from sale	$ 30,000,000
Subsequent Event | Payments Testing Business | Disposal Group, Disposed of by Sale, Not Discontinued Operations | Forecast
Subsequent Event [Line Items]
Gain on sale of business				25,000,000
Subsequent Event | Cash-settled Stock Appreciation Rights
Subsequent Event [Line Items]
Remaining outstanding shares (in shares)		118,904
Subsequent Event | 2024 Long-Term Incentive Plan
Subsequent Event [Line Items]
Aggregate value of granted equity awards		$ 17,000,000
Nonqualified stock options granted (in shares)		2,074,299
Subsequent Event | 2024 Long-Term Incentive Plan | Revision of Prior Period, Adjustment | Forecast
Subsequent Event [Line Items]
Pre-tax compensation expense				9,000,000
Subsequent Event | 2024 Long-Term Incentive Plan | Stock Appreciation Rights (SARs)
Subsequent Event [Line Items]
Decrease in shares upon conversion (in shares)		(1,978,761)
Increase in shares upon conversion (in shares)		1,978,761
Subsequent Event | 2024 Long-Term Incentive Plan | Cash-settled Stock Appreciation Rights
Subsequent Event [Line Items]
Expired CSARs (in shares)			1,334,640
Decrease in shares upon conversion (in shares)		1,978,761
Increase in shares upon conversion (in shares)		(1,978,761)
Decrease in accrued compensation upon conversion		$ 25,000,000
Increase in accrued compensation upon conversion		(25,000,000)
Subsequent Event | 2024 Long-Term Incentive Plan | Cash-settled Stock Appreciation Rights | Forecast
Subsequent Event [Line Items]
Cash paid during the period for stock-based compensation				$ 18,000,000
Subsequent Event | 2024 Long-Term Incentive Plan | Stock Appreciation Rights Reclassified
Subsequent Event [Line Items]
Decrease in accrued compensation upon conversion		(25,000,000)
Increase in accrued compensation upon conversion		$ 25,000,000
Subsequent Event | 2024 Long-Term Incentive Plan | Employee Stock Option
Subsequent Event [Line Items]
Expiration period		10 years
Vesting period		3 years
Subsequent Event | 2024 Long-Term Incentive Plan | Restricted Stock Units (RSUs)
Subsequent Event [Line Items]
Stock units granted (in shares)	711,256	22,486
Vesting period		3 years
Aggregate value	$ 25,000,000
Subsequent Event | 2024 Long-Term Incentive Plan | Performance Shares
Subsequent Event [Line Items]
Stock units granted (in shares)	382,455
Vesting period		3 years
Aggregate value	$ 13,000,000
Common Class A | Subsequent Event
Subsequent Event [Line Items]
Common stock authorized (in shares)							1,000,000,000
Common Class A | Subsequent Event | 2024 Long-Term Incentive Plan
Subsequent Event [Line Items]
Stock reserved for issuance (in shares)		20,000,000
Common Class A | Subsequent Event | IPO
Subsequent Event [Line Items]
Shares sold in IPO (in shares)		38,870,000
Price per share for IPO (in dollars per share)		$ 28.00
Proceeds from IPO		$ 0
Common Class A | Subsequent Event | Over-Allotment Option
Subsequent Event [Line Items]
Shares sold in IPO (in shares)		5,070,000
Common Class B | Subsequent Event
Subsequent Event [Line Items]
Common stock authorized (in shares)							500,000,000