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This item represents the pretax change in net unrealized holding gain (loss) on available-for-sale securities that has been included in accumulated other comprehensive income, a separate component of shareholders' equity, during the period.

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This item represents the gross profit realized on the sale of debt or equity securities categorized neither as held-to-maturity nor trading securities.

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This item represents the gross loss realized on the sale of debt or equity securities categorized neither as held-to-maturity nor trading securities and excluding other than temporary impairments (OTTI), if any, recognized elsewhere.

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No definition available.

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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 and losses recognized for other than temporary impairments (OTTI) of the subject investments.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 9
-Subparagraph (c)-(e)
-URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27357-111563

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-URI http://asc.fasb.org/extlink&oid=56944662&loc=d3e3602-108585

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.7(c),9(a))
-URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 10
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27405-111563

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The amount by which the fair value of an investment in debt and equity securities categorized as Available-for-sale 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.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27161-111563

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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No definition available.

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Investments, Gain (Loss) on Investments (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Gain (Loss) on Investments [Line Items]
Realized (losses) gains	$ (52)	$ 5,092	$ 836	$ 3,056	$ 1,228	$ 640	$ 166	$ 26,327	$ 8,932	$ 28,361	$ 1,357
Change in net unrealized gains (losses)									(5,425)	(33,718)	91,780
Gross realized gains, gross realized losses and impairment losses [Abstract]
Gross realized gains									11,909	30,039	4,966
Gross realized losses									(2,977)	(1,678)	(3,465)
Other-than-temporary-impairment losses									0	0	(144)
Net realized investment gains	$ (52)	$ 5,092	$ 836	$ 3,056	$ 1,228	$ 640	$ 166	$ 26,327	8,932	28,361	1,357
Available-for-Sale Securities
Gain (Loss) on Investments [Line Items]
Realized (losses) gains									8,932	28,361	1,357
Gross realized gains, gross realized losses and impairment losses [Abstract]
Net realized investment gains									8,932	28,361	1,357
Available-for-Sale Securities \| Fixed income
Gain (Loss) on Investments [Line Items]
Realized (losses) gains									5,310	28,335	1,000
Change in net unrealized gains (losses)									(5,403)	(33,687)	91,718
Gross realized gains, gross realized losses and impairment losses [Abstract]
Net realized investment gains									5,310	28,335	1,000
Available-for-Sale Securities \| Equity Securities
Gain (Loss) on Investments [Line Items]
Realized (losses) gains									3,622	26	356
Change in net unrealized gains (losses)									(36)	(32)	66
Gross realized gains, gross realized losses and impairment losses [Abstract]
Net realized investment gains									3,622	26	356
Available-for-Sale Securities \| Other
Gain (Loss) on Investments [Line Items]
Realized (losses) gains									0	0	1
Change in net unrealized gains (losses)									14	1	(4)
Gross realized gains, gross realized losses and impairment losses [Abstract]
Net realized investment gains									$ 0	$ 0	$ 1