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Income Taxes - Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Millions | Dec. 31, 2022 | Dec. 31, 2021
--- | --- | ---
Deferred tax assets related to: |  |
U.S. federal and state net operating and capital loss carryforwards | $ 85.4 | $ 85.7
Non-U.S. net operating loss carryforwards | 36.1 | 46.1
Incentive compensation | 21.4 | 14.5
Accrued interest | 8.8 | 7.8
Deferred acquisition costs | 8.0 | 6.4
Net unrealized investment losses | 4.7 | 0.0
Tax credit carryforwards | 1.8 | 0.2
Other items | 0.5 | 0.4
Total gross deferred tax assets | 166.7 | 161.1
Less: valuation allowances | 94.3 | 85.6
Total net deferred tax assets | 72.4 | 75.5
Deferred tax liabilities related to: |  |
Member’s surplus contributions | 71.3 | 60.4
Purchase accounting | 43.9 | 43.9
Investment basis difference | 33.9 | 26.8
Deferred underwriting | 9.7 | 4.1
Net unrealized investment gains (losses) | 0.0 | 10.7
Other items | 1.4 | 1.8
Total deferred tax liabilities | 160.2 | 147.7
Net deferred tax asset (liability) | $ (87.8) | $ (72.2)

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