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v3.23.1

Reconciliation of Total Revenue and Income Before Income Tax to Operating Revenue and Operating Income (Detail) - USD ($) $ in Millions | 3 Months Ended
--- | ---
Mar. 31, 2023 | Mar. 31, 2022
Segment Reporting, Revenue Reconciling Item |  |
Total Revenue | $ 3,036.1 | $ 2,980.6
Net Investment Gain (Loss) | 0.1 | (13.8)
Operating Segments |  |
Segment Reporting, Revenue Reconciling Item |  |
Total Revenue | 3,036.1 | 2,980.6
Net Investment Gain (Loss) | 0.1 | (13.8)
Adjusted Operating Revenue | 3,036.0 | 2,994.4
Income Before Income Tax | 451.3 | 295.7
Adjusted Operating Income | 469.5 | 335.3
Operating Segments | Closed Block Individual Disability Reinsurance Transaction |  |
Segment Reporting, Revenue Reconciling Item |  |
Amortization of the Cost of Reinsurance | (11.0) | (13.4)
Non-Contemporaneous Reinsurance | (7.3) | (12.4)
Operating Segments | Unrelated to Significant Transaction |  |
Segment Reporting, Revenue Reconciling Item |  |
Net Investment Gain (Loss) | $ 0.1 | $ (13.8)

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