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Stockholders' Equity - Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions | 3 Months Ended | 9 Months Ended
--- | --- | ---
Sep. 30, 2021 | Sep. 30, 2020 | Sep. 30, 2021 | Sep. 30, 2020
Other Comprehensive Income (Loss) |  |  |  |
Other comprehensive income (loss), pre-tax | $ (189.7) | $ 357.7 | $ (909.0) | $ 939.2
Other comprehensive income (loss), tax | 2.8 | (51.3) | 142.4 | (231.0)
Other comprehensive income (loss) | (186.9) | 306.4 | (766.6) | 708.2
Net unrealized gains (losses) on available-for-sale securities including NCI |  |  |  |
Other Comprehensive Income (Loss) |  |  |  |
Other comprehensive income (loss) before reclassifications, pre-tax | (546.4) | 960.1 | (2,461.6) | 2,378.1
Adjustments for assumed changes in amortization patterns, pre-tax | 32.2 | (109.0) | 121.3 | (112.9)
Adjustments for assumed changes in policyholder liabilities, pre-tax | 477.2 | (565.7) | 1,573.7 | (1,136.0)
Other comprehensive income (loss), pre-tax | (39.6) | 288.3 | (770.4) | 1,074.7
Other comprehensive income (loss) before reclassifications, tax | 127.4 | (200.0) | 554.9 | (500.1)
Reclassification from accumulated other comprehensive income, tax | 0.2 | (1.0) | 0.2 | 12.6
Adjustments for assumed changes in amortization patterns, tax | (6.8) | 22.9 | (25.5) | 23.7
Adjustments for assumed changes in policyholder liabilities, tax | (104.8) | 116.5 | (365.3) | 241.9
Other comprehensive income (loss), tax | 16.0 | (61.6) | 164.3 | (221.9)
Other comprehensive income (loss) before reclassifications, after-tax | (419.0) | 760.1 | (1,906.7) | 1,878.0
Reclassification from accumulated other comprehensive income, after-tax | (2.4) | 1.9 | (3.6) | (41.9)
Adjustments for assumed changes in amortization patterns, after-tax | 25.4 | (86.1) | 95.8 | (89.2)
Adjustments for assumed changes in policyholder liabilities, after-tax | 372.4 | (449.2) | 1,208.4 | (894.1)
Other comprehensive income (loss) | (23.6) | 226.7 | (606.1) | 852.8
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 | (2.6) | 2.9 | (3.8) | (54.5)
Net unrealized gains (losses) on derivative instruments including NCI |  |  |  |
Other Comprehensive Income (Loss) |  |  |  |
Other comprehensive income (loss) before reclassifications, pre-tax | 31.2 | (29.2) | 53.7 | 26.2
Reclassification from accumulated other comprehensive income, pre-tax | (3.9) | (4.6) | (13.0) | (22.8)
Adjustments for assumed changes in amortization patterns, pre-tax | (0.5) | 0.2 | (0.5) | 0.9
Adjustments for assumed changes in policyholder liabilities, pre-tax | (0.4) | 1.7 | 1.0 | 4.6
Other comprehensive income (loss), pre-tax | 26.4 | (31.9) | 41.2 | 8.9
Other comprehensive income (loss) before reclassifications, tax | (6.6) | 6.2 | (11.3) | (4.9)
Reclassification from accumulated other comprehensive income, tax | 0.8 | 0.9 | 2.7 | 4.2
Adjustments for assumed changes in amortization patterns, tax | 0.1 |  | 0.1 | (0.2)
Adjustments for assumed changes in policyholder liabilities, tax |  | (0.3) | (0.3) | (0.9)
Other comprehensive income (loss), tax | (5.7) | 6.8 | (8.8) | (1.8)
Other comprehensive income (loss) before reclassifications, after-tax | 24.6 | (23.0) | 42.4 | 21.3
Reclassification from accumulated other comprehensive income, after-tax | (3.1) | (3.7) | (10.3) | (18.6)
Adjustments for assumed changes in amortization patterns, after-tax | (0.4) | 0.2 | (0.4) | 0.7
Adjustments for assumed changes in policyholder liabilities, after-tax | (0.4) | 1.4 | 0.7 | 3.7
Other comprehensive income (loss) | 20.7 | (25.1) | 32.4 | 7.1
Foreign currency translation adjustment relating to noncontrolling interest | Net income attributable to noncontrolling interest |  |  |  |
Other Comprehensive Income (Loss) |  |  |  |
Reclassification from accumulated other comprehensive income, pre-tax |  | 8.7 |  | 8.7
Foreign currency translation adjustment including NCI |  |  |  |
Other Comprehensive Income (Loss) |  |  |  |
Other comprehensive income (loss) before reclassifications, pre-tax |  | 75.5 |  | (231.1)
Other comprehensive income (loss), pre-tax | (189.3) | 87.0 | (209.5) | (188.1)
Other comprehensive income (loss) before reclassifications, tax |  | 5.5 |  | 2.7
Reclassification from accumulated other comprehensive income, tax |  | 1.8 |  | 1.8
Other comprehensive income (loss), tax | (4.0) | 7.3 | (4.6) | 4.5
Other comprehensive income (loss) before reclassifications, after-tax |  | 81.0 |  | (228.4)
Reclassification from accumulated other comprehensive income, after-tax |  | 13.3 |  | 44.8
Other comprehensive income (loss) | (193.3) | 94.3 | (214.1) | (183.6)
Foreign currency translation adjustment including NCI | Net realized capital gains (losses) |  |  |  |
Other Comprehensive Income (Loss) |  |  |  |
Reclassification from accumulated other comprehensive income, pre-tax |  | 11.5 |  | 43.0
Unrecognized postretirement benefit obligation including NCI |  |  |  |
Other Comprehensive Income (Loss) |  |  |  |
Other comprehensive income (loss) before reclassifications, pre-tax |  |  | (9.1) | 0.6
Other comprehensive income (loss), pre-tax | 12.8 | 14.3 | 29.7 | 43.7
Other comprehensive income (loss) before reclassifications, tax |  |  | 1.9 | (0.2)
Reclassification from accumulated other comprehensive income, tax | (3.5) | (3.8) | (10.4) | (11.6)
Other comprehensive income (loss), tax | (3.5) | (3.8) | (8.5) | (11.8)
Other comprehensive income (loss) before reclassifications, after-tax |  |  | (7.2) | 0.4
Reclassification from accumulated other comprehensive income, after-tax | 9.3 | 10.5 | 28.4 | 31.5
Other comprehensive income (loss) | 9.3 | 10.5 | 21.2 | 31.9
Unrecognized postretirement benefit obligation including NCI | Operating expense |  |  |  |
Other Comprehensive Income (Loss) |  |  |  |
Reclassification from accumulated other comprehensive income, pre-tax | $ 12.8 | $ 14.3 | $ 38.8 | $ 43.1

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