Investments (Major Categories of Net Realized Gains on Investments) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Schedule of Available-for-sale Securities [Line Items]
Gain on investments	$ 1,331	$ 5,826	$ 408
Unrealized gain on investment	25,992	26,122
Other-than-temporary impairments	(2,888)	(3,323)	(274)
Net realized gain	(369)	2,503	134
Corporate Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Gain on investments	(264)		263
Collateralized Corporate Bank Loans [Member]
Schedule of Available-for-sale Securities [Line Items]
Gain on investments	(86)	126	109
Municipal Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Gain on investments	(189)	(83)	(140)
Collateralized Mortgage Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Gain on investments	(1)	240	32
Equity Securities All Others [Member]
Schedule of Available-for-sale Securities [Line Items]
Unrealized gain on investment	1,188
Other Investments [Member]
Schedule of Available-for-sale Securities [Line Items]
Unrealized gain on investment	1,188	27
Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Gain on investments	1,871	5,543	$ 144
Unrealized gain on investment	$ 21,052	$ 23,364