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Investments - Gain (Loss) on Investments (Details) - USD ($) $ in Thousands | 3 Months Ended | 6 Months Ended
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Jun. 30, 2017 | Jun. 30, 2016 | Jun. 30, 2017 | Jun. 30, 2016
Gain (Loss) on Investments [Line Items] |  |  |  |
Realized investment gains (losses) on investments: | $ (42) | $ 836 | $ (164) | $ 3,892
Realized investment gains (losses) on investments: |  |  |  |
Gains on sales | 644 | 1,404 | 829 | 5,509
Losses on sales | (686) | (568) | (993) | (1,617)
Net realized investment (losses) gains | (42) | 836 | (164) | 3,892
Fixed maturities |  |  |  |
Gain (Loss) on Investments [Line Items] |  |  |  |
Realized investment gains (losses) on investments: | (52) | 831 | (177) | 3,886
Realized investment gains (losses) on investments: |  |  |  |
Net realized investment (losses) gains | (52) | 831 | (177) | 3,886
Equity securities |  |  |  |
Gain (Loss) on Investments [Line Items] |  |  |  |
Realized investment gains (losses) on investments: | 10 | 5 | 13 | 6
Realized investment gains (losses) on investments: |  |  |  |
Net realized investment (losses) gains | $ 10 | $ 5 | $ 13 | $ 6

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- Definition This item represents the gross profit realized on the sale of debt or equity securities categorized neither as held-to-maturity nor trading securities. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 9 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=82897076&loc=d3e27357-111563 + Details
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- Definition 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. + References 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=82897076&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=98514028&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=63488584&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=82897076&loc=d3e27405-111563 + Details
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