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Income Taxes (Deferred Tax Assets and Liabilities) (Details) - USD ($) $ in Millions |  |  | 12 Months Ended
--- | --- | --- | ---
Dec. 22, 2017 | Dec. 21, 2017 | Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2017
Deferred tax assets related to: |  |  |  |  |
U.S. federal and state net operating and capital loss carryforwards |  |  | $ 92.3 | $ 95.5 |
Non-U.S. net operating loss carryforwards |  |  | 41.7 | 36.6 |
Incentive compensation |  |  | 15.0 | 14.1 |
Investment basis difference |  |  | 0.0 | 11.1 |
Net unrealized investment losses |  |  | 0.0 | 9.5 |
Accrued interest |  |  | 5.1 | 0.0 |
Deferred acquisition costs |  |  | 4.3 | 3.5 |
Tax credit carryforwards |  |  | 4.2 | 4.2 |
Other items |  |  | 3.4 | 5.8 |
Total gross deferred tax assets |  |  | 166.0 | 180.3 |
Less: valuation allowances |  |  | 77.9 | 139.9 |
Total net deferred tax assets |  |  | 88.1 | 40.4 |
Deferred tax liabilities related to: |  |  |  |  |
Net unrealized investment gains |  |  | 66.3 | 0.0 |
Member’s surplus contributions |  |  | 43.2 | 32.8 |
Investment basis difference |  |  | 6.6 | 0.0 |
Other items |  |  | 4.6 | 5.4 |
Total deferred tax liabilities |  |  | 120.7 | 38.2 |
Net deferred tax (liability) asset |  |  |  | $ 2.2 |
Net deferred tax (liability) asset |  |  | $ 32.6 |  |
U.S. statutory rate (as a percent) | 21.00% | 35.00% | 21.00% | 35.00% |
Percentage of utilization of net operating losses |  |  |  | 80.00% |
Change in valuation allowance |  |  | $ (63.6) | $ 31.0 | $ (42.6)
United States |  |  |  |  |
Deferred tax liabilities related to: |  |  |  |  |
Provisional income tax expense |  |  | $ 43.1 |  |

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