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Investments (Other Investment Portfolio by Strategy and the Remaining Commitment Amount and Maximum Exposure to Loss Associated With Each Strategy) (Details) - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended |
--- | --- | --- | ---
Sep. 30, 2020 | Sep. 30, 2019 | Sep. 30, 2020 | Sep. 30, 2019 | Dec. 31, 2019
Net investment income earned |  | $ 68,185 | $ 55,826 | $ 158,596 | $ 164,949 |
Carrying Value |  | 258,648 |  | 258,648 |  | $ 216,807
Alternative Investments [Member] |  |  |  |  |  |
Net investment income earned |  | 18,700 | $ 5,200 | 8,900 | $ 13,000 |
Other Securities [Member] |  |  |  |  |  |
Carrying Value |  | 40,725 |  | 40,725 |  | 32,667
Remaining Commitment |  | 0 |  | 0 |  | 0
Maximum Exposure to Loss | [1] | 40,725 |  | 40,725 |  | 32,667
Alternative Investments [Member] |  |  |  |  |  |
Carrying Value |  | 217,923 |  | 217,923 |  | 184,140
Remaining Commitment |  | 225,374 |  | 225,374 |  | 219,219
Maximum Exposure to Loss | [1] | 443,297 |  | 443,297 |  | 403,359
Alternative Investments [Member] | Private Equity Funds [Member] |  |  |  |  |  |
Carrying Value |  | 146,810 |  | 146,810 |  | 118,352
Remaining Commitment |  | 110,173 |  | 110,173 |  | 93,138
Maximum Exposure to Loss | [1] | 256,983 |  | 256,983 |  | 211,490
Alternative Investments [Member] | Private Credit Funds [Member] |  |  |  |  |  |
Carrying Value |  | 49,254 |  | 49,254 |  | 42,532
Remaining Commitment |  | 96,131 |  | 96,131 |  | 105,340
Maximum Exposure to Loss | [1] | 145,385 |  | 145,385 |  | 147,872
Alternative Investments [Member] | Real Assets [Member] |  |  |  |  |  |
Carrying Value |  | 21,859 |  | 21,859 |  | 23,256
Remaining Commitment |  | 19,070 |  | 19,070 |  | 20,741
Maximum Exposure to Loss | [1] | 40,929 |  | 40,929 |  | 43,997
Other Investments [Member] |  |  |  |  |  |
Carrying Value |  | 258,648 |  | 258,648 |  | 216,807
Remaining Commitment |  | 225,374 |  | 225,374 |  | 219,219
Maximum Exposure to Loss | [1] | $ 484,022 |  | $ 484,022 |  | $ 436,026
[1] | The maximum exposure to loss includes both the carry value of these investments and the related remaining commitments. In addition, tax credits that have been previously recognized in Other securities are subject to the risk of recapture, which we do not consider significant.

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- Definition This item represents contractual obligations to invest additional amounts on our other investment portfolio. These additional investments may or may not be required. + References No definition available. + Details
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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/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 220 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-04(2)) -URI http://asc.fasb.org/extlink&oid=120400993&loc=SL114874131-224263 + Details
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