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Reportable Segments - Financial performance (Details) - USD ($) $ in Millions | 3 Months Ended | 9 Months Ended
--- | --- | ---
Sep. 30, 2021 | Sep. 30, 2020 | Sep. 30, 2021 | Sep. 30, 2020
Segment Reporting Information |  |  |  |
Adjusted net income | $ 727 | $ 475 | $ 2,428 | $ 208
Net investment income | 764 | 464 | 2,446 | 930
Realized capital gains (losses) | 105 | 319 | 818 | 597
Pension and other postretirement remeasurement gains (losses) | (40) | 71 | 404 | (320)
Curtailment gains (losses) | 0 | 8 | 0 | 8
Business combination expense and amortization of purchased intangibles | (34) | (28) | (124) | (81)
Business combination fair value adjustment | 0 | 0 | 6 | 0
Income tax expense | (14) | (317) | (990) | (798)
Income (loss) from discontinued operations | 235 | (86) | (3,435) | (289)
Income tax benefit from discontinued operations | 90 | 23 | 163 | 82
Income (loss) from discontinued operations, net of tax | 325 | (63) | (3,272) | (207)
Less: Net loss attributable to noncontrolling interest | (7) | 0 | (7) | 0
Net income applicable to common shareholders | 508 | 1,126 | 695 | 2,863
Allstate Protection |  |  |  |
Segment Reporting Information |  |  |  |
Underwriting income (loss) | (421) | 887 | 1,670 | 3,143
Run-off Property-Liability |  |  |  |
Segment Reporting Information |  |  |  |
Underwriting income (loss) | (113) | (135) | (118) | (141)
Property-Liability |  |  |  |
Segment Reporting Information |  |  |  |
Underwriting income (loss) | (534) | 752 | 1,552 | 3,002
Net investment income | 710 | 422 | 2,314 | 802
Realized capital gains (losses) | 94 | 292 | 763 | 571
Protection Services |  |  |  |
Segment Reporting Information |  |  |  |
Adjusted net income | 45 | 40 | 150 | 115
Allstate Health and Benefits |  |  |  |
Segment Reporting Information |  |  |  |
Adjusted net income | 33 | 33 | 160 | 62
Net investment income | 18 | 18 | 56 | 58
Realized capital gains (losses) | (1) | 3 | 5 | 0
Corporate and Other |  |  |  |
Segment Reporting Information |  |  |  |
Adjusted net income | $ (95) | $ (111) | $ (330) | $ (317)

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