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Stockholders' Equity - Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions | 3 Months Ended
--- | ---
Mar. 31, 2023 | Mar. 31, 2022
Other Comprehensive Income (Loss) |  |
Other comprehensive income (loss), pre-tax | $ 822.0 | $ (1,787.3)
Other comprehensive income (loss), tax | (142.9) | 410.9
Other comprehensive income (loss) | 679.1 | (1,376.4)
Net unrealized gains (losses) on available-for-sale securities including NCI |  |
Other Comprehensive Income (Loss) |  |
Other comprehensive income (loss) before reclassifications, pre-tax | 1,280.8 | (5,535.5)
Adjustments for assumed changes in amortization patterns, pre-tax | 0.2 | (0.1)
Adjustments for assumed changes in policyholder liabilities, pre-tax | (0.1) | 363.1
Other comprehensive income (loss), pre-tax | 1,359.4 | (5,213.1)
Other comprehensive income (loss) before reclassifications, tax | (264.9) | 1,172.0
Reclassification from accumulated other comprehensive income, tax | (16.4) | 5.2
Adjustments for assumed changes in policyholder liabilities, tax |  | (76.3)
Other comprehensive income (loss), tax | (281.3) | 1,100.9
Other comprehensive income (loss) before reclassifications, after-tax | 1,015.9 | (4,363.5)
Reclassification from accumulated other comprehensive income, after-tax | 62.1 | (35.4)
Adjustments for assumed changes in amortization patterns, after-tax | 0.2 | (0.1)
Adjustments for assumed changes in policyholder liabilities, after-tax | (0.1) | 286.8
Other comprehensive income (loss) | 1,078.1 | (4,112.2)
Net unrealized gains (losses) on available-for-sale securities including NCI | Net realized capital gains (losses) |  |
Other Comprehensive Income (Loss) |  |
Reclassification from accumulated other comprehensive income, pre-tax | 78.5 | (40.6)
Net unrealized gains (losses) on derivative instruments including NCI |  |
Other Comprehensive Income (Loss) |  |
Other comprehensive income (loss) before reclassifications, pre-tax | 3.7 | (21.0)
Reclassification from accumulated other comprehensive income, pre-tax | (3.7) | (6.8)
Adjustments for assumed changes in policyholder liabilities, pre-tax |  | 3.9
Other comprehensive income (loss), pre-tax |  | (23.9)
Other comprehensive income (loss) before reclassifications, tax | (0.8) | 4.4
Reclassification from accumulated other comprehensive income, tax | 0.8 | 1.4
Adjustments for assumed changes in policyholder liabilities, tax |  | (0.7)
Other comprehensive income (loss), tax |  | 5.1
Other comprehensive income (loss) before reclassifications, after-tax | 2.9 | (16.6)
Reclassification from accumulated other comprehensive income, after-tax | (2.9) | (5.4)
Adjustments for assumed changes in policyholder liabilities, after-tax |  | 3.2
Other comprehensive income (loss) |  | (18.8)
Liability for future policy benefits discount rate remeasurement gain (loss) |  |
Other Comprehensive Income (Loss) |  |
Other comprehensive income (loss), pre-tax | (682.4) | 3,190.9
Other comprehensive income (loss), tax | 141.5 | (671.8)
Other comprehensive income (loss) | (540.9) | 2,519.1
Market risk benefit nonperformance risk gain |  |
Other Comprehensive Income (Loss) |  |
Other comprehensive income (loss), pre-tax | 7.7 | 93.2
Other comprehensive income (loss), tax | (1.7) | (19.5)
Other comprehensive income (loss) | 6.0 | (73.7)
Foreign currency translation adjustment including NCI |  |
Other Comprehensive Income (Loss) |  |
Other comprehensive income (loss), pre-tax | 132.2 | 156.6
Other comprehensive income (loss), tax | (0.1) | (1.5)
Other comprehensive income (loss) | 132.1 | 155.1
Unrecognized postretirement benefit obligation including NCI |  |
Other Comprehensive Income (Loss) |  |
Other comprehensive income (loss), pre-tax | 5.1 | 9.0
Reclassification from accumulated other comprehensive income, tax | (1.3) | (2.3)
Other comprehensive income (loss), tax | (1.3) | (2.3)
Reclassification from accumulated other comprehensive income, after-tax | 3.8 | 6.7
Other comprehensive income (loss) | 3.8 | 6.7
Unrecognized postretirement benefit obligation including NCI | Operating expense |  |
Other Comprehensive Income (Loss) |  |
Reclassification from accumulated other comprehensive income, pre-tax | $ 5.1 | $ 9.0

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