Investments (Allowance for Credit Losses) (Details) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2020	Dec. 31, 2019
Allowance for Loan and Lease Losses [Roll Forward]
Balance, beginning of year	$ 1,768	$ 2,065
Cumulative effect of adoption of ASU 2016-13	2,487
Addition to (release of) allowance for credit losses		(297)
Addition to (release of) allowance for expected losses	304
Total ending balance	4,559	1,768
Commercial Mortgage Loans
Allowance for Loan and Lease Losses [Roll Forward]
Balance, beginning of year	1,743	2,026
Cumulative effect of adoption of ASU 2016-13	2,495
Addition to (release of) allowance for credit losses		(283)
Addition to (release of) allowance for expected losses	311
Total ending balance	4,549	1,743
Agricultural Property Loans
Allowance for Loan and Lease Losses [Roll Forward]
Balance, beginning of year	25	39
Cumulative effect of adoption of ASU 2016-13	(8)
Addition to (release of) allowance for credit losses		(14)
Addition to (release of) allowance for expected losses	(7)
Total ending balance	10	25
Other collateralized loans
Allowance for Loan and Lease Losses [Roll Forward]
Balance, beginning of year	0	0
Cumulative effect of adoption of ASU 2016-13	0
Addition to (release of) allowance for credit losses		0
Addition to (release of) allowance for expected losses	0
Total ending balance	$ 0	$ 0