Stockholders' and Members' Equity - Additional Information (Details)
 3 Months Ended 6 Months Ended 12 Months Ended
Dec. 31, 2022
USD ($)
Vote
$ / shares
shares
Sep. 30, 2022
shares
Jun. 30, 2022
shares
Mar. 31, 2022
shares
Jun. 30, 2021
shares
Dec. 31, 2022
USD ($)
Vote
$ / shares
shares
Dec. 31, 2020
shares
Dec. 31, 2019
shares
Aug. 01, 2022
USD ($)
$ / shares
Dec. 31, 2021
$ / shares
shares
Jul. 02, 2021
shares
Class Of Stock [Line Items]                      
Preferred stock, authorized 1,000,000         1,000,000       1,000,000  
Preferred stock, par value | $ / shares $ 0.0001         $ 0.0001       $ 0.0001  
Preferred stock, issued 0         0       0  
Preferred stock, outstanding 0         0       0  
Common stock, par value | $ / shares                 $ 0.0001    
Increase in equity | $           $ 141,000,000          
Additional paid-in-capital deferred tax liabilities | $           12,000,000          
Additional paid-in-capital deferred tax assets | $           3,000,000          
Common stock repurchase, authorized amount | $                 $ 100,000,000    
Remaining authorized amount for future share repurchase program | $ $ 88,000,000         88,000,000          
Tax Receivable Agreement Liability                      
Class Of Stock [Line Items]                      
Additional TRA liability | $           $ 43,000,000          
Class A Common Stock                      
Class Of Stock [Line Items]                      
Common stock, shares issued 478,340,245         478,340,245       464,103,972  
Common stock, shares outstanding 478,340,245         478,340,245       464,103,972  
Common stock, par value | $ / shares $ 0.0001         $ 0.0001       $ 0.0001  
Common stock, shares authorized 1,000,000,000         1,000,000,000       1,000,000,000  
Conversion of stock           13,978,222          
Number of shares repurchased           1,506,385          
Total cost | $           $ 12,000,000          
Unvested Class A common stock                      
Class Of Stock [Line Items]                      
Common stock, shares issued 7,583,284         7,583,284          
Common stock, shares outstanding 7,583,284         7,583,284          
Common stock, par value | $ / shares $ 0.0001         $ 0.0001          
Class B Common Stock                      
Class Of Stock [Line Items]                      
Common stock, shares issued 9,980,906         9,980,906       9,980,906  
Common stock, shares outstanding 9,980,906         9,980,906       9,980,906  
Common stock, par value | $ / shares $ 0.0001         $ 0.0001       $ 0.0001  
Issuance of common units           14,999,998          
Common stock, shares authorized 20,000,000         20,000,000       20,000,000  
Unvested Common Class B                      
Class Of Stock [Line Items]                      
Issuance of employee compensation           797,386          
Class B-1 Common Stock                      
Class Of Stock [Line Items]                      
Common stock, shares issued 4,990,453         4,990,453          
Common stock, shares outstanding 4,990,453         4,990,453          
Common stock, par value | $ / shares $ 0.0001         $ 0.0001          
Common stock shares related to employee compensation, unvested 398,693         398,693          
Common stock conversion, description           Class B-1 common shares 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 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           $ 12.5          
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 2,509,546         2,509,546          
Common stock, shares outstanding 2,509,546         2,509,546          
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           $ 12.5          
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-2 Common Stock                      
Class Of Stock [Line Items]                      
Common stock, shares issued 4,990,453         4,990,453          
Common stock, shares outstanding 4,990,453         4,990,453          
Common stock, par value | $ / shares $ 0.0001         $ 0.0001          
Common stock shares related to employee compensation, unvested 398,693         398,693          
Common stock conversion, description           Class B-2 common shares vest and automatically convert into shares of Class A common shares on a 1-for-1 basis if the VWAP of the Class A common shares 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          
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          
Class B-2 Common Units | Alight Holdings                      
Class Of Stock [Line Items]                      
Common stock, shares issued 2,509,546         2,509,546          
Common stock, shares outstanding 2,509,546         2,509,546          
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 Class A common shares 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          
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          
Class B-3 Common Stock                      
Class Of Stock [Line Items]                      
Common stock, shares issued 0         0          
Common stock, shares outstanding 0         0          
Common stock, par value | $ / shares $ 0.0001         $ 0.0001          
Common stock, shares authorized 10,000,000         10,000,000          
Class V Common Stock                      
Class Of Stock [Line Items]                      
Common stock, shares issued 63,481,465         63,481,465       77,459,687  
Common stock, shares outstanding 63,481,465         63,481,465       77,459,687  
Common stock, par value | $ / shares $ 0.0001         $ 0.0001       $ 0.0001  
Common stock shares conversion ratio           1          
Common stock, shares authorized 175,000,000         175,000,000       175,000,000  
Common shares, votes per share | Vote 1         1          
Shares, outstanding 63,481,465 75,800,317 75,886,716 76,220,431   63,481,465       77,459,687  
Conversion of stock (12,318,852) (86,399) (333,715) (1,239,256)              
Class Z Common Stock                      
Class Of Stock [Line Items]                      
Common stock, shares issued 5,595,577         5,595,577       5,595,577 8,671,507
Common stock, shares outstanding 5,595,577         5,595,577       5,595,577  
Common stock, par value | $ / shares $ 0.0001         $ 0.0001       $ 0.0001  
Common stock, shares authorized 12,900,000         12,900,000       12,900,000  
Shares, outstanding 5,595,577 5,595,577 5,595,577 5,595,577   5,595,577       5,595,577  
Class Z-A Common Stock                      
Class Of Stock [Line Items]                      
Common stock, shares issued 5,046,819         5,046,819          
Common stock, shares outstanding 5,046,819         5,046,819          
Common stock, par value | $ / shares $ 0.0001         $ 0.0001          
Class Z-B-1 Common Stock                      
Class Of Stock [Line Items]                      
Common stock, shares issued 274,379         274,379          
Common stock, shares outstanding 274,379         274,379          
Common stock, par value | $ / shares $ 0.0001         $ 0.0001          
Class Z-B-2 Common Stock                      
Class Of Stock [Line Items]                      
Common stock, shares issued 274,379         274,379          
Common stock, shares outstanding 274,379         274,379          
Common stock, par value | $ / shares $ 0.0001         $ 0.0001          
Class Z Common Units                      
Class Of Stock [Line Items]                      
Common stock, shares issued 3,075,930         3,075,930          
Common stock, shares outstanding 3,075,930         3,075,930          
Class Z-A Common Units                      
Class Of Stock [Line Items]                      
Common stock, shares issued 2,774,272         2,774,272          
Common stock, shares outstanding 2,774,272         2,774,272          
Class Z-B-1 Common Units                      
Class Of Stock [Line Items]                      
Common stock, shares issued 150,829         150,829          
Common stock, shares outstanding 150,829         150,829          
Class Z-B-2 Common Units                      
Class Of Stock [Line Items]                      
Common stock, shares issued 150,829         150,829          
Common stock, shares outstanding 150,829         150,829          
Class A Units                      
Class Of Stock [Line Items]                      
Common stock, shares outstanding 541,821,710         541,821,710          
Shares, outstanding 478,340,245         478,340,245          
Held by non controlling interest           63,481,465          
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