Investments (Allowance for Losses) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Allowance for Loan and Lease Losses [Roll Forward]
Allowance for credit losses, beginning of year	$ 482	$ 1,256	$ 2,177
Addition to (release of) allowance for losses	161	(774)	(921)
Allowance for credit losses, end of year	643	482	1,256
Agricultural Property Loans
Allowance for Loan and Lease Losses [Roll Forward]
Allowance for credit losses, beginning of year	100	100
Allowance for credit losses, end of year	$ 100	$ 100	$ 100