Unpaid Claims - Additional information (Details)
3 Months Ended 12 Months Ended
Mar. 31, 2021
USD ($)
Mar. 31, 2020
USD ($)
Dec. 31, 2020
USD ($)
Dec. 31, 2019
USD ($)
Roll Forward In Liability For Unpaid Claims And Claims Adjustment Expense [Abstract]        
Unpaid Claims $ 117,582,000 $ 90,353,000 $ 103,976,000 $ 77,886,000
Prior years 70,367,000 $ 59,359,000 $ 63,039 $ 37,742,000
Unfavorable development recognized $ 1,300,000      
Ratio of current year medical claims paid as a percent of current year net medical claims 6,120 5,090 83.0 83.1