Investments (Major Categories of Net Realized Gains on Investments) (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Schedule of Available-for-sale Securities [Line Items]
Gain on investments	$ 6,799	$ 1,331	$ 5,826
Unrealized gain on investment	25,734	25,992
Unrealized loss on investment	3,416	4,869
Other-than-temporary impairments	(5,877)	(2,888)	(3,323)
Net realized gain	(205)	(369)	2,503
Corporate Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Gain on investments	(468)	(264)
Collateralized Corporate Bank Loans [Member]
Schedule of Available-for-sale Securities [Line Items]
Gain on investments	79	(86)	126
Municipal Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Gain on investments	195	(189)	(83)
Collateralized Mortgage Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Gain on investments	(9)	(1)	240
Equity Securities All Others [Member]
Schedule of Available-for-sale Securities [Line Items]
Unrealized gain on investment		1,188
Unrealized loss on investment	1,127
Other Investments [Member]
Schedule of Available-for-sale Securities [Line Items]
Unrealized gain on investment	61	1,188
Parent Company [Member]
Schedule of Available-for-sale Securities [Line Items]
Net realized gain	(759)
Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Gain on investments	7,002	1,871	$ 5,543
Unrealized gain on investment	23,014	21,052
Unrealized loss on investment	$ 1,504	$ 790

Amount of unrealized gain before deducting unrealized loss on investments in debt and equity securities classified as available-for-sale securities.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=73527792&loc=d3e27161-111563

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Amount of unrealized loss before deducting unrealized gain on investments in available-for-sale securities.

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
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This item represents the net total realized and unrealized gain (loss) included in earnings for the period as a result of selling or holding marketable securities categorized as trading, available-for-sale, or held-to-maturity, including the unrealized holding gain (loss) of held-to-maturity securities transferred to the trading security category and the cumulative unrealized gain (loss) which was included in other comprehensive income (a separate component of shareholders' equity) for available-for-sale securities transferred to trading securities during the period. Additionally, this item would include any gains (losses) realized during the period from the sale of investments accounted for under the cost method of accounting.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
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The amount by which the fair value of an investment is less than the amortized cost basis or carrying amount of that investment at the balance sheet date and the decline in fair value is deemed to be other than temporary, before considering whether or not such amount is recognized in earnings or other comprehensive income.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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