General form of registration statement for all companies including face-amount certificate companies

FAIR VALUE MEASUREMENTS - Assets measured on recurring basis (Details)

v3.20.4
FAIR VALUE MEASUREMENTS - Assets measured on recurring basis (Details) - Recurring - USD ($)
$ in Thousands
Sep. 30, 2020
Dec. 31, 2019
Dec. 31, 2018
Assets      
Total assets at fair value $ 87,038 $ 150,209 $ 89,059
Money market funds      
Assets      
Total assets at fair value 33,858 40,454 24,380
Assetbacked securities      
Assets      
Total assets at fair value 3,105 16,806 13,285
Corporate bonds      
Assets      
Total assets at fair value 30,084 67,948 50,944
Repurchase agreements      
Assets      
Total assets at fair value   25,001 450
Government bonds      
Assets      
Total assets at fair value 19,991 25,001  
Level 1      
Assets      
Total assets at fair value 53,849 40,454 24,380
Level 1 | Money market funds      
Assets      
Total assets at fair value 33,858 40,454 24,380
Level 1 | Government bonds      
Assets      
Total assets at fair value 19,991    
Level 2      
Assets      
Total assets at fair value 33,189 109,755 64,229
Level 2 | Assetbacked securities      
Assets      
Total assets at fair value 3,105 16,806 13,285
Level 2 | Corporate bonds      
Assets      
Total assets at fair value $ 30,084 67,948 50,944
Level 2 | Repurchase agreements      
Assets      
Total assets at fair value   25,001  
Level 2 | Government bonds      
Assets      
Total assets at fair value   $ 25,001  
Level 3      
Assets      
Total assets at fair value     450
Level 3 | Repurchase agreements      
Assets      
Total assets at fair value     $ 450