XML 62 R66.htm IDEA: XBRL DOCUMENT v3.19.3.a.u2
Reinsurance - Additional Information (Detail) - USD ($)
 12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Insurance [Abstract]      
Paid losses recoverable outstanding due date 90 days    
Paid losses recoverable past due $ 0    
Received reinsurance recoveries $ 2,000,000.0 $ 1,300,000 $ 1,600,000
Unsecured reinsurance recoverable by reinsurer reporting threshold 1.50%