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Schedule I - Summay of Investments - Other Than Investments in Related Parties (Details) $ in Thousands | Dec. 31, 2015 USD ($)
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Amortized Cost or Cost | $ 5,020,045
Carrying Amount | 5,089,269
Held-to-maturity Securities [Member] |
Amortized Cost or Cost | 201,054
Fair Value | 209,544
Carrying Amount | 201,354
Held-to-maturity Securities [Member] | Obligations of States and Political Subdivisions [Member] |
Amortized Cost or Cost | 175,269
Fair Value | 181,880
Carrying Amount | 176,117
Held-to-maturity Securities [Member] | Public utilities [Member] |
Amortized Cost or Cost | 9,637
Fair Value | 10,662
Carrying Amount | 9,647
Held-to-maturity Securities [Member] | All Other Corporate Securities [Member] |
Amortized Cost or Cost | 10,591
Fair Value | 11,353
Carrying Amount | 10,396
Held-to-maturity Securities [Member] | Asset-backed Securities [Member] |
Amortized Cost or Cost | 1,030
Fair Value | 1,028
Carrying Amount | 910
Held-to-maturity Securities [Member] | Commercial Mortgage-backed Securities (CMBS) [Member] |
Amortized Cost or Cost | 4,527
Fair Value | 4,621
Carrying Amount | 4,284
AFS Fixed Income Securities [Member] |
Amortized Cost or Cost | 4,352,514
Fair Value | 4,408,203
Carrying Amount | 4,408,203
AFS Fixed Income Securities [Member] | U.S. Government and Government Agencies [Member] |
Amortized Cost or Cost | 99,485
Fair Value | 104,115
Carrying Amount | 104,115
AFS Fixed Income Securities [Member] | Foreign Government Obligations [Member] |
Amortized Cost or Cost | 14,885
Fair Value | 15,181
Carrying Amount | 15,181
AFS Fixed Income Securities [Member] | Obligations of States and Political Subdivisions [Member] |
Amortized Cost or Cost | 1,314,779
Fair Value | 1,359,142
Carrying Amount | 1,359,142
AFS Fixed Income Securities [Member] | Public utilities [Member] |
Amortized Cost or Cost | 156,786
Fair Value | 157,270
Carrying Amount | 157,270
AFS Fixed Income Securities [Member] | All Other Corporate Securities [Member] |
Amortized Cost or Cost | 1,735,510
Fair Value | 1,742,912
Carrying Amount | 1,742,912
AFS Fixed Income Securities [Member] | Asset-backed Securities [Member] |
Amortized Cost or Cost | 244,541
Fair Value | 244,154
Carrying Amount | 244,154
AFS Fixed Income Securities [Member] | Commercial Mortgage-backed Securities (CMBS) [Member] |
Amortized Cost or Cost | 245,252
Fair Value | 243,592
Carrying Amount | 243,592
AFS Fixed Income Securities [Member] | Residential Mortgage Backed Securities (RMBS) [Member] |
Amortized Cost or Cost | 541,276
Fair Value | 541,837
Carrying Amount | 541,837
Common Stock [Member] |
Amortized Cost or Cost | 181,991
Fair Value | 194,789
Carrying Amount | 194,789
Common Stock [Member] | Public Utility, Equities [Member] |
Amortized Cost or Cost | 9,106
Fair Value | 10,080
Carrying Amount | 10,080
Common Stock [Member] | Banks, Trust and Insurance Companies [Member] |
Amortized Cost or Cost | 23,622
Fair Value | 23,696
Carrying Amount | 23,696
Common Stock [Member] | Industrial, Miscellaneous, and All Other [Member] |
Amortized Cost or Cost | 149,263
Fair Value | 161,013
Carrying Amount | 161,013
Preferred Stock [Member] |
Amortized Cost or Cost | 11,825
Fair Value | 12,262
Carrying Amount | 12,262
Preferred Stock [Member] | Banks, Trust and Insurance Companies [Member] |
Amortized Cost or Cost | 11,825
Fair Value | 12,262
Carrying Amount | 12,262
Equity Securities [Member] |
Amortized Cost or Cost | 193,816
Fair Value | 207,051
Carrying Amount | 207,051
Short-term Investments [Member] |
Amortized Cost or Cost | 194,819
Fair Value | 194,819
Carrying Amount | 194,819
Other Investments [Member] |
Amortized Cost or Cost | 77,842
Carrying Amount | $ 77,842

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- Definition This element represents the carrying (reported) amount of the entity's investments as of the balance sheet date. This amount may represent the individual investment's or group of similar investments' original cost, fair value, or such other amount at which the investment is shown in the entity's balance sheet. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 946 -SubTopic 320 -Section S99 -Paragraph 7 -Subparagraph (SX 210.12-15) -URI http://asc.fasb.org/extlink&oid=50485924&loc=d3e611379-123010 + Details
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