Investments (Major Categories of Net Investment Gains (Losses) on Investments) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Schedule of Available-for-sale Securities [Line Items]
Gain on investments	$ 1,803	$ 6,799
Unrealized gain on investment	24,959	25,734
Unrealized loss on investment	19,785	3,416
Other-than-temporary impairments	0	(5,877)
Gain (Loss) on Investments, Total	(10,195)	(205)
Other Investments [Member]
Schedule of Available-for-sale Securities [Line Items]
Unrealized gain on investment		61
Unrealized loss on investment	2,615
Corporate Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Gain on investments	(83)	(468)
Collateralized Corporate Bank Loans [Member]
Schedule of Available-for-sale Securities [Line Items]
Gain on investments	90	79
Municipal Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Gain on investments	1,435	195
Collateralized Mortgage Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Gain on investments	2	(9)
Equity Securities All Others [Member]
Schedule of Available-for-sale Securities [Line Items]
Unrealized loss on investment	2,676	1,127
Equity Securities [Member] | Other Investments [Member]
Schedule of Available-for-sale Securities [Line Items]
Unrealized loss on investment	9,322
Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Gain on investments	359	7,002
Unrealized gain on investment	20,693	23,014
Unrealized loss on investment	$ 8,506	$ 1,504