Stockholders' Equity - Additional Information (Details)			6 Months Ended	12 Months Ended
	Aug. 16, 2023 $ / shares shares	Mar. 06, 2023 $ / shares shares	Jun. 30, 2021 shares	Dec. 31, 2023 USD ($) Vote $ / shares shares	Dec. 31, 2020 shares	Dec. 31, 2019 shares	Dec. 31, 2022 $ / shares shares	Aug. 01, 2022 USD ($) $ / shares	Jul. 02, 2021 shares
Class Of Stock [Line Items]
Preferred stock, authorized				1,000,000			1,000,000
Preferred stock, par value | $ / shares				$ 0.0001			$ 0.0001
Preferred stock, issued				0			0
Preferred stock, outstanding				0			0
Common stock, par value | $ / shares								$ 0.0001
Increase in equity | $				$ 344,000,000
Additional paid-in-capital deferred tax liabilities | $				43,000,000
Common stock repurchase, authorized amount | $								$ 100,000,000
Remaining authorized amount for future share repurchase program | $				48,000,000
Tax Receivable Agreement Liability
Class Of Stock [Line Items]
Additional TRA liability | $				$ 109,000,000
Class A Common Stock
Class Of Stock [Line Items]
Common stock, shares issued				510,888,937			478,300,000
Common stock, shares outstanding				510,888,937			478,300,000
Common stock, par value | $ / shares				$ 0.0001			$ 0.0001
Common stock, shares authorized				1,000,000,000			1,000,000,000
Conversion of stock				34,519,247
Number of shares repurchased				4,921,468
Total cost | $				$ 40,000,000
Class A Common Stock | Secondary Offering
Class Of Stock [Line Items]
Number of shares issued	22,500,000	46,000,000
Public offering price | $ / shares	$ 7.98	$ 9
Number of days option to underwriter to purchase additional common shares		30 days
Class A Common Stock | Over-Allotment Option
Class Of Stock [Line Items]
Number of shares issued		6,900,000
Unvested Class A common stock
Class Of Stock [Line Items]
Common stock, shares issued				3,321,260
Common stock, shares outstanding				3,321,260
Class B Common Stock
Class Of Stock [Line Items]
Common stock, shares issued				9,900,000			10,000,000
Common stock, shares outstanding				9,900,000			10,000,000
Common stock, par value | $ / shares				$ 0.0001			$ 0.0001
Issuance of common units				14,999,998
Common stock, shares authorized				20,000,000			20,000,000
Unvested Common Class B
Class Of Stock [Line Items]
Issuance of employee compensation				470,760
Class B-1 Common Stock
Class Of Stock [Line Items]
Common stock, shares issued				4,951,235
Common stock, shares outstanding				4,951,235
Common stock shares related to employee compensation, unvested				235,380
Common stock conversion, description				Shares of Class B-1 Common Stock vest and automatically convert into shares of Class A Common Stock on a 1-for-1 basis if the volume weighted average price (“VWAP”) of the shares of Class A Common Stock equals or exceeds $12.50 per share for 20 or more trading days within a consecutive 30-trading day period (or in the event of a change of control or liquidation event that implies a $12.50 per share valuation on a diluted basis).
Common stock shares conversion ratio				1
Common stock shares convertible stock price trigger | $ / shares				$ 12.50
Common stock shares convertible threshold trading days				20 days
Common stock shares convertible threshold consecutive trading days				30 days
Common stock shares convertible stock valuation price on diluted basis | $ / shares				$ 12.5
Class B-1 Common Shares | Alight Holdings
Class Of Stock [Line Items]
Common stock, shares issued				2,548,764
Common stock, shares outstanding				2,548,764
Common stock conversion, description				Class B-1 common units vest and automatically convert into Class A common units of Alight Holdings on a 1-for-1 basis if the VWAP of the Class A common shares equals or exceeds $12.50 per share for 20 or more trading days within a consecutive 30-trading day period (or in the event of a change of control or liquidation event that implies a $12.50 per share valuation on a diluted basis).
Common stock shares conversion ratio				1
Common stock shares convertible stock price trigger | $ / shares				$ 12.50
Common stock shares convertible threshold trading days				20 days
Common stock shares convertible threshold consecutive trading days				30 days
Common stock shares convertible stock valuation price on diluted basis | $ / shares				$ 12.50
Class B-2 Common Stock
Class Of Stock [Line Items]
Common stock, shares issued				4,951,235
Common stock, shares outstanding				4,951,235
Common stock, par value | $ / shares				$ 0.0001
Common stock shares related to employee compensation, unvested				235,380
Common stock conversion, description				Class B-2 Common Stock vest and automatically convert into shares of Class A common shares on a 1-for-1 basis if the VWAP of the shares of Class A Common Stock equals or exceeds $15.00 per share for 20 or more trading days within a consecutive 30-trading day period (or in the event of a change of control or liquidation event that implies a $15.00 per share valuation on a diluted basis).
Common stock shares conversion ratio				1
Common stock shares convertible stock price trigger | $ / shares				$ 15.00
Common stock shares convertible threshold trading days				20 days
Common stock shares convertible threshold consecutive trading days				30 days
Common stock shares convertible stock valuation price on diluted basis | $ / shares				$ 15.00
Class B-2 Common Units | Alight Holdings
Class Of Stock [Line Items]
Common stock, shares issued				2,548,764
Common stock, shares outstanding				2,548,764
Common stock conversion, description				Class B-2 common units vest and automatically convert into Class A common units of Alight Holdings on a 1-for-1 basis if the VWAP of the shares of Class A Common Stock equals or exceeds $15.00 per share for 20 or more trading days within a consecutive 30-trading day period (or in the event of a change of control or liquidation event that implies a $15.00 per share valuation on a diluted basis).
Common stock shares conversion ratio				1
Common stock shares convertible stock price trigger | $ / shares				$ 15.00
Common stock shares convertible threshold trading days				20 days
Common stock shares convertible threshold consecutive trading days				30 days
Common stock shares convertible stock valuation price on diluted basis | $ / shares				$ 15.00
Class B-3 Common Stock
Class Of Stock [Line Items]
Common stock, shares issued				0
Common stock, shares outstanding				0
Common stock, par value | $ / shares				$ 0.0001
Common stock, shares authorized				10,000,000
Class V Common Stock
Class Of Stock [Line Items]
Common stock, shares issued				29,000,000			63,500,000
Common stock, shares outstanding				29,000,000			63,500,000
Common stock, par value | $ / shares				$ 0.0001			$ 0.0001
Common stock shares conversion ratio				1
Common stock, shares authorized				175,000,000			175,000,000
Common shares, votes per share | Vote				1
Shares, outstanding				28,962,218			63,481,465
Shares issued				28,962,218
Conversion of stock				(34,519,247)
Class Z Common Stock
Class Of Stock [Line Items]
Common stock, shares issued				3,420,215			5,600,000		8,671,507
Common stock, shares outstanding				3,420,215			5,600,000
Common stock, par value | $ / shares				$ 0.0001			$ 0.0001
Common stock, shares authorized				12,900,000			12,900,000
Shares, outstanding				3,420,215			5,595,577
Class Z-A Common Stock
Class Of Stock [Line Items]
Common stock, shares issued				2,988,649
Common stock, shares outstanding				2,988,649
Class Z-B-1 Common Stock
Class Of Stock [Line Items]
Common stock, shares issued				215,783
Common stock, shares outstanding				215,783
Class Z-B-2 Common Stock
Class Of Stock [Line Items]
Common stock, shares issued				215,783
Common stock, shares outstanding				215,783
Class Z Common Units
Class Of Stock [Line Items]
Common stock, shares outstanding				1,880,117
Class Z-A Common Units
Class Of Stock [Line Items]
Common stock, shares issued				1,642,881
Common stock, shares outstanding				1,642,881
Class Z-B-1 Common Units
Class Of Stock [Line Items]
Common stock, shares issued				118,618
Common stock, shares outstanding				118,618
Class Z-B-2 Common Units
Class Of Stock [Line Items]
Common stock, shares issued				118,618
Common stock, shares outstanding				118,618
Class A Units
Class Of Stock [Line Items]
Common stock, shares outstanding				539,851,156
Shares, outstanding				510,888,938
Held by non controlling interest				28,962,218
Common Class A
Class Of Stock [Line Items]
Common units/stock voting rights				Each holder of Class A common units is entitled to one vote per unit.
Common Class A | Alight Holdings
Class Of Stock [Line Items]
Common units granted			0		0
Common Class A-1 Units
Class Of Stock [Line Items]
Common units/stock voting rights				Holders of Class A-1 common units are not entitled to voting rights.
Common Class A-1 Units | Alight Holdings
Class Of Stock [Line Items]
Common units granted			643		0
Common Class B Units
Class Of Stock [Line Items]
Common units/stock voting rights				Holders of Class B common units are not entitled to voting rights.
Common Class B Units | Alight Holdings
Class Of Stock [Line Items]
Common units granted			0		7,459	2,587