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Comprehensive Income - Schedule of Changes in Balances of Each Component of Accumulated Other Comprehensive Income (Details) - USD ($) $ in Millions | 3 Months Ended
--- | ---
Mar. 31, 2024 | Mar. 31, 2023
Changes In Accumulated Other Comprehensive Income [Roll Forward] |  |
Beginning Balance | $ (160) | $ (253)
Other comprehensive income before reclassifications | 14 | (33)
Amounts reclassified from accumulated other comprehensive income | (1) | 3
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent | (15) | 36
Ending Balance | (175) | (217)
Income Tax Expense (Benefit) | 5 | 4
Realized Investment Gains (Losses) | 1 | (4)
Unrealized Gains (Losses) on Available-for-Sale Securities [Member] |  |
Changes In Accumulated Other Comprehensive Income [Roll Forward] |  |
Beginning Balance | (20) | (71)
Other comprehensive income before reclassifications | 6 | (14)
Amounts reclassified from accumulated other comprehensive income | (1) | 4
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent | (7) | 17
Ending Balance | (27) | (54)
Realized Investment Gains (Losses) | (1) | 4
Accumulated Translation Adjustment [Member] |  |
Changes In Accumulated Other Comprehensive Income [Roll Forward] |  |
Beginning Balance | (144) | (184)
Other comprehensive income before reclassifications | 8 | (16)
Amounts reclassified from accumulated other comprehensive income | 0 | 0
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent | (8) | 16
Ending Balance | (152) | (168)
Accumulated Gain (Loss), Financial Liability, Fair Value Option, Attributable to Parent [Member] |  |
Changes In Accumulated Other Comprehensive Income [Roll Forward] |  |
Beginning Balance | (1) | (1)
Other comprehensive income before reclassifications | 0 | 0
Amounts reclassified from accumulated other comprehensive income | 0 | 0
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent | 0 | 0
Ending Balance | (1) | (1)
Other Postretirement Benefits Plan [Member] |  |
Changes In Accumulated Other Comprehensive Income [Roll Forward] |  |
Beginning Balance | 5 | 3
Other comprehensive income before reclassifications | 0 | (3)
Amounts reclassified from accumulated other comprehensive income | 0 | 0
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent | 0 | 3
Ending Balance | 5 | 6
Reclassification out of Accumulated Other Comprehensive Income [Member] | Unrealized Gains (Losses) on Available-for-Sale Securities [Member] |  |
Changes In Accumulated Other Comprehensive Income [Roll Forward] |  |
Income Tax Expense (Benefit) | 0 | (1)
Reclassification out of Accumulated Other Comprehensive Income [Member] | Other Postretirement Benefits Plan [Member] |  |
Accumulated Other Comprehensive Income (Loss) [Line Items] |  |
Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit), Reclassification Adjustment from AOCI, before Tax | 0 | 0
Changes In Accumulated Other Comprehensive Income [Roll Forward] |  |
Amounts reclassified from accumulated other comprehensive income | 0 | 0
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), Reclassification Adjustment from AOCI, before Tax | 0 | 0
Income (Loss) from Continuing Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest | 0 | 0
Income Tax Expense (Benefit) | $ 0 | $ 0

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