Investments (Allowance for Losses) (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2016	Dec. 31, 2015
Allowance for Loan and Lease Losses [Roll Forward]
Allowance for credit losses, beginning of year	$ 643	$ 482
Addition to (release of) allowance for losses	6	161
Charge-offs, net of recoveries	0	0
Total ending balance	649	643
Commercial Mortgage Loans
Allowance for Loan and Lease Losses [Roll Forward]
Allowance for credit losses, beginning of year	622	455
Addition to (release of) allowance for losses	17	167
Charge-offs, net of recoveries	0	0
Total ending balance	639	622
Agricultural Property Loans
Allowance for Loan and Lease Losses [Roll Forward]
Allowance for credit losses, beginning of year	21	27
Addition to (release of) allowance for losses	(11)	(6)
Charge-offs, net of recoveries	0	0
Total ending balance	10	21
Uncollateralized Loans
Allowance for Loan and Lease Losses [Roll Forward]
Allowance for credit losses, beginning of year	0	0
Addition to (release of) allowance for losses	0	0
Charge-offs, net of recoveries	0	0
Total ending balance	$ 0	$ 0