Business combination - Additional Information (Details) - USD ($)
 1 Months Ended 3 Months Ended 12 Months Ended
Jan. 07, 2021
Jan. 06, 2021
Oct. 05, 2020
Feb. 28, 2019
Jan. 31, 2021
Mar. 31, 2021
Mar. 31, 2020
Dec. 31, 2020
Dec. 31, 2019
Apr. 24, 2020
Apr. 21, 2020
Dec. 31, 2017
Nov. 30, 2016
Business Acquisition [Line Items]                          
Common Stock, Par or Stated Value Per Share               $ 0.0001 $ 0.0001        
Proceeds from Issuance of Common Stock           $ 1,282,000 $ 155,000 $ 1,748,000 $ 601,000        
Common stock, shares, outstanding               89,206,266 88,279,119        
Common stock. conversion basis         2.0681                
Exercise price of warrants                       $ 3.45 $ 2.61
Cash paid for redemption of common stock               $ (957,000)          
Warrants outstanding 38,533,271                        
Preferred stock, shares authorized           0   155,387,025 155,387,025        
Preferred stock, par value per share           $ 0.0001   $ 0.0001          
Preferred stock, shares issued           0   139,444,346 139,444,346        
Preferred stock, shares outstanding           0   139,444,346 139,444,346        
Goodwill               $ 1,243,000 $ 1,243,000        
Board of Directors [Member]                          
Business Acquisition [Line Items]                          
Preferred stock, shares authorized           25,000,000              
Preferred stock, par value per share           $ 0.0001              
Preferred stock, shares issued           0              
Preferred stock, shares outstanding           0              
Private Placement Warrant [Member]                          
Business Acquisition [Line Items]                          
Class of warrant or right, numbers issued 10,933,333                        
Public Warrants [Member]                          
Business Acquisition [Line Items]                          
Class of warrant or right, numbers issued 27,599,938                        
Private Placement Warrant and Public Warrant [Member]                          
Business Acquisition [Line Items]                          
Exercise price of warrants $ 11.50                        
Equity Method Investment, Ownership Percentage       100.00%                  
Business Combination, Consideration Transferred       $ 1,400,000                  
Goodwill       $ 1,200,000                  
Common Class A [Member]                          
Business Acquisition [Line Items]                          
Common Stock, Par or Stated Value Per Share           $ 0.0001   $ 0.0001          
Common stock, shares, outstanding 143,475,108         148,279,247   0          
Common Class A [Member] | Public Warrants [Member]                          
Business Acquisition [Line Items]                          
Exercise price of warrants           $ 11.50              
Common Class A [Member] | Clover Health Investments Corp [Member]                          
Business Acquisition [Line Items]                          
Common Stock, Voting Rights one vote                        
Common Class A [Member] | SCH Sponsor III LLC [Member]                          
Business Acquisition [Line Items]                          
Sale of stock, number of shares issued in transaction     15,200,000                    
Common Class B [Member]                          
Business Acquisition [Line Items]                          
Common Stock, Par or Stated Value Per Share $ 0.0001         $ 0.0001   $ 0.0001          
Common Stock, Voting Rights 10 votes per share                        
Cash consideration received from business combination $ 499,800,000                        
Common stock, shares, outstanding 260,965,701         259,821,838   89,206,266          
Share Price $ 10.00                        
Common stock. conversion basis 2.0681                        
Pro rata adjustments, percentage 32.30%                        
Common Class A and Class B [Member]                          
Business Acquisition [Line Items]                          
Common stock, shares, outstanding 404,440,809                        
SCH class B ordinary shares converted to Clover class A common Stock [Member] | Social Capital Hedosophia Holdings Corp III [Member]                          
Business Acquisition [Line Items]                          
Common Stock, Par or Stated Value Per Share                     $ 0.0001    
Common stock. conversion basis one-for-one                        
SCH class A ordinary shares converted to Clover class A common Stock [Member] | Social Capital Hedosophia Holdings Corp III [Member]                          
Business Acquisition [Line Items]                          
Common Stock, Par or Stated Value Per Share                   $ 0.0001 $ 0.0001    
Common stock. conversion basis one-for-one                        
Shares redeemed for cash   24,892                      
Sale of Stock, Price Per Share   $ 10.00                      
Cash paid for redemption of common stock   $ 200,000                      
Redemption price per share   $ 10.00                      
Cash held-in-trust account   $ 827,900,000                      
Balance to pay on merger consideration   $ 499,800,000                      
PIPE Investment [Member]                          
Business Acquisition [Line Items]                          
Business combination, proceeds from private placement     $ 400,000         $ 400,000,000          
PIPE Investment [Member] | Common Class A [Member]                          
Business Acquisition [Line Items]                          
Proceeds from Issuance of Common Stock     $ 400,000,000                    
Sale of stock, number of shares issued in transaction     40,000,000                    
IPO [Member]                          
Business Acquisition [Line Items]                          
Business combination, deferred underwriter fees $ 29,000,000             29,000,000          
SCH and Merger Sub [Member]                          
Business Acquisition [Line Items]                          
Business combination, net increase in cash               670,000,000          
Business combination, transaction costs               $ 61,800,000          
SCH and Merger Sub [Member] | Merger Agreement [Member]                          
Business Acquisition [Line Items]                          
Business combination, net increase in cash 670,000,000                        
Business combination, transaction costs $ 61,000,000