Investments in Fixed Maturity Securities (HTM Allowance for Credit Loss) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Debt Securities, Held-to-maturity, Allowance for Credit Loss [Roll Forward]
Allowance for expected credit losses at January 1, 2020	$ 798	$ 0
Held-to-maturity, allowance for credit loss	387	798
Provision for expected credit losses	(411)	729
Allowance for expected credit losses at September 30, 2020	387	798
Cumulative Effect, Period Of Adoption, Adjustment
Debt Securities, Held-to-maturity, Allowance for Credit Loss [Roll Forward]
Allowance for expected credit losses at January 1, 2020	$ 0	69
Held-to-maturity, allowance for credit loss		0
Allowance for expected credit losses at September 30, 2020		$ 0