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Life and Annuity Benefits (Liability for Future Policy Benefit, Activity) (Details) - USD ($) $ in Thousands | 9 Months Ended |  |
--- | --- | --- | ---
Sep. 30, 2024 | Sep. 30, 2023 | Dec. 31, 2023 | Dec. 31, 2022
Liability for Future Policy Benefits and Unpaid Claims and Claims Adjustment Expense [Abstract] |  |  |  |  |
Liability for future policyholder benefits, beginning of year |  | $ 557,763 | $ 554,366 |  |
Liability for future policyholder benefits at original discount rate, beginning of year |  | 642,877 | 667,761 |  |
Effect of changes in cash flow assumptions |  |  |  | $ 0 | $ 0
Effect of actual variances from expected experience |  |  |  | (4,745) | $ (5,890)
Adjusted liability for future policyholder benefits, beginning of year |  | 638,132 | 661,871 |  |
Interest accretion |  | 10,596 | 11,251 |  |
Benefit payments |  | (37,083) | (39,819) |  |
Effect of foreign currency changes |  | 4,450 | (356) |  |
Liability for future policy holder benefits t original discount rate, end of period |  | 616,095 | 632,947 |  |
Cumulative effect of changes in discount rate assumptions |  | (82,700) | (124,511) |  |
Liability for future policyholder benefits, beginning of year, ending of period | [1] | 533,395 | $ 508,436 |  |
Undiscounted liability for future policyholder benefits |  | $ 787,600 |  | $ 813,600 |
[1] | The undiscounted liability for future policyholder benefits was $787.6 million and $813.6 million as of September 30, 2024 and 2023, respectively.

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- Definition Amount, before tax, of accumulated other comprehensive income (loss) (AOCI) from (increase) decrease in expected future policy benefit component of liability for future policy benefit from change in discount rate. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 944 -SubTopic 40 -Name Accounting Standards Codification -Section 50 -Paragraph 6 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480081/944-40-50-6 Reference 2: http://www.xbrl.org/2003/role/exampleRef -Topic 944 -SubTopic 40 -Name Accounting Standards Codification -Section 55 -Paragraph 13I -Subparagraph (h) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480046/944-40-55-13I Reference 3: http://www.xbrl.org/2003/role/exampleRef -Topic 944 -SubTopic 40 -Name Accounting Standards Codification -Section 55 -Paragraph 29E -Publisher FASB -URI https://asc.fasb.org/1943274/2147480046/944-40-55-29E Reference 4: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 944 -SubTopic 40 -Name Accounting Standards Codification -Section 65 -Paragraph 2 -Subparagraph (g)(1) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480016/944-40-65-2 + Details
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- Definition Amount, before effect of reinsurance and after current period update of cash flow assumption, of expected future benefit and expense component for liability for future policy benefit, discounted at original rate. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 944 -SubTopic 40 -Name Accounting Standards Codification -Section 50 -Paragraph 6 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480081/944-40-50-6 Reference 2: http://www.xbrl.org/2003/role/exampleRef -Topic 944 -SubTopic 40 -Name Accounting Standards Codification -Section 55 -Paragraph 29E -Publisher FASB -URI https://asc.fasb.org/1943274/2147480046/944-40-55-29E Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 944 -SubTopic 40 -Name Accounting Standards Codification -Section 65 -Paragraph 2 -Subparagraph (g)(1) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480016/944-40-65-2 + Details
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- Definition Amount of cumulative increase (decrease) in expected future policy benefit and expense component for liability of future policy benefit from effect of variance from cash flow assumption change for actual experience. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 944 -SubTopic 40 -Name Accounting Standards Codification -Section 50 -Paragraph 6 -Subparagraph (b)(2) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480081/944-40-50-6 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 944 -SubTopic 40 -Name Accounting Standards Codification -Section 50 -Paragraph 6 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480081/944-40-50-6 Reference 3: http://www.xbrl.org/2003/role/exampleRef -Topic 944 -SubTopic 40 -Name Accounting Standards Codification -Section 55 -Paragraph 29E -Publisher FASB -URI https://asc.fasb.org/1943274/2147480046/944-40-55-29E Reference 4: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 944 -SubTopic 40 -Name Accounting Standards Codification -Section 65 -Paragraph 2 -Subparagraph (g)(1) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480016/944-40-65-2 Reference 5: http://www.xbrl.org/2003/role/exampleRef -Topic 944 -SubTopic 40 -Name Accounting Standards Codification -Section 55 -Paragraph 13I -Subparagraph (f) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480046/944-40-55-13I + Details
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