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Investments (Net Investment Income) (Details) - USD ($) $ in Thousands | 3 Months Ended | 6 Months Ended
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Jun. 30, 2016 | Jun. 30, 2015 | Jun. 30, 2016 | Jun. 30, 2015
Net Investment Income [Line Items] |  |  |  |
Net investment income earned | $ 31,182 | $ 32,230 | $ 61,951 | $ 59,147
Fixed Income Securities [Member] |  |  |  |
Net Investment Income [Line Items] |  |  |  |
Net investment income earned | 31,753 | 30,659 | 63,397 | 61,626
Equity Securities [Member] |  |  |  |
Net Investment Income [Line Items] |  |  |  |
Net investment income earned | 2,204 | 2,384 | 4,434 | 4,176
Short-Term Investments [Member] |  |  |  |
Net Investment Income [Line Items] |  |  |  |
Net investment income earned | 142 | 23 | 301 | 48
Other Investments [Member] |  |  |  |
Net Investment Income [Line Items] |  |  |  |
Net investment income earned | (611) | 1,422 | (1,677) | (2,118)
Investment Expenses [Member] |  |  |  |
Net Investment Income [Line Items] |  |  |  |
Net investment income earned | $ (2,306) | $ (2,258) | $ (4,504) | $ (4,585)

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- Definition Amount, after investment expense, of income earned from investments in securities and real estate. Includes, but is not limited to, real estate investment, policy loans, dividends, and interest. Excludes realized gain (loss) on investments. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 225 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-04(2)) -URI http://asc.fasb.org/extlink&oid=6879464&loc=d3e573970-122913 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 235 -Section S99 -Paragraph 1 -Subparagraph (SX 210.12-16(Column G)) -URI http://asc.fasb.org/extlink&oid=34713774&loc=d3e574960-122915 + Details
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- Definition 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. + References No definition available. + Details
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