Investments (Credit Losses Recognized in Earnings on Fixed Maturity Securities Held by the Company) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Roll Forward]
Balance, beginning of period	$ 7,284	$ 7,284	$ 11,696
Other than Temporary Impairment, Credit Losses Recognized in Earnings, Additions, Additional Credit Losses	231	0	0
Other than Temporary Impairment, Credit Losses Recognized in Earnings, Reductions, Securities Sold	(1,502)	0	(4,412)
Balance, end of period	$ 6,013	$ 7,284	$ 7,284