Supplemental Consolidated Cash and Cash Flow Information (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019	Dec. 31, 2018
Supplemental Cash Flow Elements [Abstract]
Cash		$ 64,778		$ 25,206
Restricted cash		697		302
Total cash and restricted cash shown in the Consolidated Balance Sheets	$ 39,349	65,475	$ 39,349	$ 25,508	$ 11,906
Interest		9,258	6,948
Income taxes		$ 18,456	12,696
Transfer of investments and policy loans	2,100,000
Reinsurance block of in-force fixed and variable annuity business	$ 2,900,000		$ 2,900,000