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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 | 6 Months Ended |
--- | --- | --- | ---
Jun. 30, 2022 | Jun. 30, 2021 | Jun. 30, 2022 | Jun. 30, 2021 | Dec. 31, 2021
Net investment income earned |  | $ 70,222 | $ 83,731 | $ 142,824 | $ 153,447 |
Other Investments |  | 429,546 |  | 429,546 |  | $ 409,032
Alternative Investments [Member] |  |  |  |  |  |
Net investment income earned |  | 9,300 | $ 29,900 | 28,400 | $ 50,100 |
Other Securities [Member] |  |  |  |  |  |
Other Investments |  | 56,230 |  | 56,230 |  | 49,300
Remaining Commitment |  | 0 |  | 0 |  | 0
Maximum Exposure to Loss | [1] | 56,230 |  | 56,230 |  | 49,300
Alternative Investments [Member] |  |  |  |  |  |
Other Investments |  | 373,316 |  | 373,316 |  | 359,732
Remaining Commitment |  | 246,694 |  | 246,694 |  | 214,987
Maximum Exposure to Loss | [1] | 620,010 |  | 620,010 |  | 574,719
Alternative Investments [Member] | Private Equity Funds [Member] |  |  |  |  |  |
Other Investments |  | 289,965 |  | 289,965 |  | 273,070
Remaining Commitment |  | 124,342 |  | 124,342 |  | 99,734
Maximum Exposure to Loss | [1] | 414,307 |  | 414,307 |  | 372,804
Alternative Investments [Member] | Private Credit Funds [Member] |  |  |  |  |  |
Other Investments |  | 56,805 |  | 56,805 |  | 63,138
Remaining Commitment |  | 92,436 |  | 92,436 |  | 92,674
Maximum Exposure to Loss | [1] | 149,241 |  | 149,241 |  | 155,812
Alternative Investments [Member] | Real Assets [Member] |  |  |  |  |  |
Other Investments |  | 26,546 |  | 26,546 |  | 23,524
Remaining Commitment |  | 29,916 |  | 29,916 |  | 22,579
Maximum Exposure to Loss | [1] | 56,462 |  | 56,462 |  | 46,103
Other Investments [Member] |  |  |  |  |  |
Other Investments |  | 429,546 |  | 429,546 |  | 409,032
Remaining Commitment |  | 246,694 |  | 246,694 |  | 214,987
Maximum Exposure to Loss | [1] | $ 676,240 |  | $ 676,240 |  | $ 624,019
[1] | In addition to the amounts in this table, previously recognized tax credits are subject to the risk of recapture. We do not consider the risk of recapture to be significant and therefore do not reflect this risk in the Maximum Exposure to Loss column in this table.

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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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