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Fair Value Measurements - Quantitative Information for Level 3 Measurements (Details) - Recurring Fair Value Measurements $ in Millions | Sep. 30, 2020 USD ($) item | Dec. 31, 2019 USD ($) item
--- | --- | ---
Unobservable inputs |  |
Assets measured at fair value | $ | $ 243,100.7 | $ 240,519.2
Liabilities measured at fair value | $ | (713.9) | (530.8)
Fair value hierarchy Level 3 |  |
Unobservable inputs |  |
Assets measured at fair value | $ | 9,227.9 | 9,421.5
Liabilities measured at fair value | $ | (563.3) | (230.5)
Fair value hierarchy Level 3 | Investment and universal life contracts |  |
Unobservable inputs |  |
Liabilities measured at fair value | $ | $ (552.4) | $ (214.2)
Embedded derivative, Valuation technique | us-gaap:ValuationTechniqueDiscountedCashFlowMember | us-gaap:ValuationTechniqueDiscountedCashFlowMember
Fair value hierarchy Level 3 | Investment and universal life contracts | Discounted cash flow | Long duration interest rate | Minimum |  |
Unobservable inputs |  |
Embedded derivative, Input | 0.010 | 0.020
Fair value hierarchy Level 3 | Investment and universal life contracts | Discounted cash flow | Long duration interest rate | Maximum |  |
Unobservable inputs |  |
Embedded derivative, Input | 0.011 | 0.021
Fair value hierarchy Level 3 | Investment and universal life contracts | Discounted cash flow | Long duration interest rate | Weighted average input |  |
Unobservable inputs |  |
Embedded derivative, Input | 0.011 |
Fair value hierarchy Level 3 | Investment and universal life contracts | Discounted cash flow | Long-term equity market volatility | Minimum |  |
Unobservable inputs |  |
Embedded derivative, Input | 0.169 | 0.150
Fair value hierarchy Level 3 | Investment and universal life contracts | Discounted cash flow | Long-term equity market volatility | Maximum |  |
Unobservable inputs |  |
Embedded derivative, Input | 0.281 | 0.269
Fair value hierarchy Level 3 | Investment and universal life contracts | Discounted cash flow | Long-term equity market volatility | Weighted average input |  |
Unobservable inputs |  |
Embedded derivative, Input | 0.193 |
Fair value hierarchy Level 3 | Investment and universal life contracts | Discounted cash flow | Non-performance risk | Minimum |  |
Unobservable inputs |  |
Embedded derivative, Input | 0.002 | 0.002
Fair value hierarchy Level 3 | Investment and universal life contracts | Discounted cash flow | Non-performance risk | Maximum |  |
Unobservable inputs |  |
Embedded derivative, Input | 0.017 | 0.013
Fair value hierarchy Level 3 | Investment and universal life contracts | Discounted cash flow | Non-performance risk | Weighted average input |  |
Unobservable inputs |  |
Embedded derivative, Input | 0.011 |
Fair value hierarchy Level 3 | Investment and universal life contracts | Discounted cash flow | Lapse rate | Minimum |  |
Unobservable inputs |  |
Embedded derivative, Input | 0.000 | 0.000
Fair value hierarchy Level 3 | Investment and universal life contracts | Discounted cash flow | Lapse rate | Maximum |  |
Unobservable inputs |  |
Embedded derivative, Input | 0.160 | 0.180
Fair value hierarchy Level 3 | Investment and universal life contracts | Discounted cash flow | Lapse rate | Weighted average input |  |
Unobservable inputs |  |
Embedded derivative, Input | 0.059 |
Fair value hierarchy Level 3 | Corporate debt securities | Available-for-sale |  |
Unobservable inputs |  |
Assets measured at fair value | $ | $ 272.3 | $ 72.5
Fixed maturities, available-for-sale, Valuation technique | us-gaap:ValuationTechniqueDiscountedCashFlowMember | us-gaap:ValuationTechniqueDiscountedCashFlowMember
Fair value hierarchy Level 3 | Corporate debt securities | Available-for-sale | Discounted cash flow | Discount rate | Minimum |  |
Unobservable inputs |  |
Fixed maturities, available-for-sale, Input | 0.011 | 0.019
Fair value hierarchy Level 3 | Corporate debt securities | Available-for-sale | Discounted cash flow | Discount rate | Maximum |  |
Unobservable inputs |  |
Fixed maturities, available-for-sale, Input | 0.117 | 0.051
Fair value hierarchy Level 3 | Corporate debt securities | Available-for-sale | Discounted cash flow | Discount rate | Weighted average input |  |
Unobservable inputs |  |
Fixed maturities, available-for-sale, Input | 0.072 | 0.038
Fair value hierarchy Level 3 | Corporate debt securities | Available-for-sale | Discounted cash flow | Illiquidity premium | Minimum |  |
Unobservable inputs |  |
Fixed maturities, available-for-sale, Input | 0 | 0
Fair value hierarchy Level 3 | Corporate debt securities | Available-for-sale | Discounted cash flow | Illiquidity premium | Maximum |  |
Unobservable inputs |  |
Fixed maturities, available-for-sale, Input | 0.0060 | 0.0410
Fair value hierarchy Level 3 | Corporate debt securities | Available-for-sale | Discounted cash flow | Illiquidity premium | Weighted average input |  |
Unobservable inputs |  |
Fixed maturities, available-for-sale, Input | 0.0020 | 0.0152
Fair value hierarchy Level 3 | Corporate debt securities | Available-for-sale | Discounted cash flow | Comparability adjustment | Minimum |  |
Unobservable inputs |  |
Fixed maturities, available-for-sale, Input | 0 |
Fair value hierarchy Level 3 | Corporate debt securities | Available-for-sale | Discounted cash flow | Comparability adjustment | Maximum |  |
Unobservable inputs |  |
Fixed maturities, available-for-sale, Input | 0.0583 |
Fair value hierarchy Level 3 | Corporate debt securities | Available-for-sale | Discounted cash flow | Comparability adjustment | Weighted average input |  |
Unobservable inputs |  |
Fixed maturities, available-for-sale, Input | 0.0195 |
Fair value hierarchy Level 3 | Corporate debt securities | Available-for-sale | Discounted cash flow | Probability of default | Minimum |  |
Unobservable inputs |  |
Fixed maturities, available-for-sale, Input | 0.000 |
Fair value hierarchy Level 3 | Corporate debt securities | Available-for-sale | Discounted cash flow | Probability of default | Maximum |  |
Unobservable inputs |  |
Fixed maturities, available-for-sale, Input | 1.000 |
Fair value hierarchy Level 3 | Corporate debt securities | Available-for-sale | Discounted cash flow | Probability of default | Weighted average input |  |
Unobservable inputs |  |
Fixed maturities, available-for-sale, Input | 0.003 |
Fair value hierarchy Level 3 | Corporate debt securities | Available-for-sale | Discounted cash flow | Potential loss severity | Minimum |  |
Unobservable inputs |  |
Fixed maturities, available-for-sale, Input | 0.000 |
Fair value hierarchy Level 3 | Corporate debt securities | Available-for-sale | Discounted cash flow | Potential loss severity | Maximum |  |
Unobservable inputs |  |
Fixed maturities, available-for-sale, Input | 0.546 |
Fair value hierarchy Level 3 | Corporate debt securities | Available-for-sale | Discounted cash flow | Potential loss severity | Weighted average input |  |
Unobservable inputs |  |
Fixed maturities, available-for-sale, Input | 0.002 |
Fair value hierarchy Level 3 | Commercial mortgage-backed securities | Available-for-sale |  |
Unobservable inputs |  |
Assets measured at fair value | $ | $ 1.2 | $ 2.4
Fixed maturities, available-for-sale, Valuation technique | us-gaap:ValuationTechniqueDiscountedCashFlowMember | us-gaap:ValuationTechniqueDiscountedCashFlowMember
Fair value hierarchy Level 3 | Commercial mortgage-backed securities | Available-for-sale | Discounted cash flow | Probability of default |  |
Unobservable inputs |  |
Fixed maturities, available-for-sale, Input | 1.000 | 1.000
Fair value hierarchy Level 3 | Commercial mortgage-backed securities | Available-for-sale | Discounted cash flow | Probability of default | Weighted average input |  |
Unobservable inputs |  |
Fixed maturities, available-for-sale, Input | 1.000 | 1.000
Fair value hierarchy Level 3 | Commercial mortgage-backed securities | Available-for-sale | Discounted cash flow | Potential loss severity |  |
Unobservable inputs |  |
Fixed maturities, available-for-sale, Input | 0.766 | 0.531
Fair value hierarchy Level 3 | Commercial mortgage-backed securities | Available-for-sale | Discounted cash flow | Potential loss severity | Weighted average input |  |
Unobservable inputs |  |
Fixed maturities, available-for-sale, Input | 0.766 | 0.531
Fair value hierarchy Level 3 | Collateralized debt obligations | Available-for-sale |  |
Unobservable inputs |  |
Assets measured at fair value | $ | $ 0.7 | $ 108.7
Fixed maturities, available-for-sale, Valuation technique | us-gaap:ValuationTechniqueDiscountedCashFlowMember | us-gaap:ValuationTechniqueDiscountedCashFlowMember
Fair value hierarchy Level 3 | Collateralized debt obligations | Available-for-sale | Discounted cash flow | Discount rate | Minimum |  |
Unobservable inputs |  |
Fixed maturities, available-for-sale, Input |  | 0.029
Fair value hierarchy Level 3 | Collateralized debt obligations | Available-for-sale | Discounted cash flow | Discount rate | Maximum |  |
Unobservable inputs |  |
Fixed maturities, available-for-sale, Input |  | 0.100
Fair value hierarchy Level 3 | Collateralized debt obligations | Available-for-sale | Discounted cash flow | Discount rate | Weighted average input |  |
Unobservable inputs |  |
Fixed maturities, available-for-sale, Input |  | 0.034
Fair value hierarchy Level 3 | Collateralized debt obligations | Available-for-sale | Discounted cash flow | Probability of default |  |
Unobservable inputs |  |
Fixed maturities, available-for-sale, Input | 1.000 | 1.000
Fair value hierarchy Level 3 | Collateralized debt obligations | Available-for-sale | Discounted cash flow | Probability of default | Weighted average input |  |
Unobservable inputs |  |
Fixed maturities, available-for-sale, Input | 1.000 | 1.000
Fair value hierarchy Level 3 | Collateralized debt obligations | Available-for-sale | Discounted cash flow | Potential loss severity |  |
Unobservable inputs |  |
Fixed maturities, available-for-sale, Input | 0.422 | 0.230
Fair value hierarchy Level 3 | Collateralized debt obligations | Available-for-sale | Discounted cash flow | Potential loss severity | Weighted average input |  |
Unobservable inputs |  |
Fixed maturities, available-for-sale, Input | 0.422 | 0.230
Fair value hierarchy Level 3 | Other debt obligations | Available-for-sale |  |
Unobservable inputs |  |
Assets measured at fair value | $ | $ 0.9 | $ 1.2
Fixed maturities, available-for-sale, Valuation technique | us-gaap:ValuationTechniqueDiscountedCashFlowMember | us-gaap:ValuationTechniqueDiscountedCashFlowMember
Fair value hierarchy Level 3 | Other debt obligations | Available-for-sale | Discounted cash flow | Discount rate |  |
Unobservable inputs |  |
Fixed maturities, available-for-sale, Input | 0.100 | 0.050
Fair value hierarchy Level 3 | Other debt obligations | Available-for-sale | Discounted cash flow | Discount rate | Weighted average input |  |
Unobservable inputs |  |
Fixed maturities, available-for-sale, Input | 0.100 | 0.050
Fair value hierarchy Level 3 | Other debt obligations | Available-for-sale | Discounted cash flow | Illiquidity premium |  |
Unobservable inputs |  |
Fixed maturities, available-for-sale, Input | 0.0500 | 0.0500
Fair value hierarchy Level 3 | Other debt obligations | Available-for-sale | Discounted cash flow | Illiquidity premium | Weighted average input |  |
Unobservable inputs |  |
Fixed maturities, available-for-sale, Input | 0.0500 | 0.0500
Fair value hierarchy Level 3 | Other investments |  |
Unobservable inputs |  |
Assets measured at fair value | $ | $ 28.9 | $ 14.8
Fair value hierarchy Level 3 | Other investments | Discounted cash flow, other investments | Discount rate | Minimum |  |
Unobservable inputs |  |
Other investments, Input | 0.250 | 0.250
Fair value hierarchy Level 3 | Other investments | Discounted cash flow, other investments | Discount rate | Maximum |  |
Unobservable inputs |  |
Other investments, Input | 0.300 | 0.300
Fair value hierarchy Level 3 | Other investments | Discounted cash flow, other investments | Discount rate | Weighted average input |  |
Unobservable inputs |  |
Other investments, Input | 0.275 | 0.275
Fair value hierarchy Level 3 | Other investments | Discounted cash flow, other investments | Terminal earnings before interest, taxes, depreciation and amortization multiple | Minimum |  |
Unobservable inputs |  |
Other investments, Input | 3.8 | 3.5
Fair value hierarchy Level 3 | Other investments | Discounted cash flow, other investments | Terminal earnings before interest, taxes, depreciation and amortization multiple | Maximum |  |
Unobservable inputs |  |
Other investments, Input | 4.7 | 4.5
Fair value hierarchy Level 3 | Other investments | Discounted cash flow, other investments | Terminal earnings before interest, taxes, depreciation and amortization multiple | Weighted average input |  |
Unobservable inputs |  |
Other investments, Input | 4.2 | 4.0
Fair value hierarchy Level 3 | Other investments | Market comparables | Revenue multiples | Minimum |  |
Unobservable inputs |  |
Other investments, Input | 6.0 | 0.8
Fair value hierarchy Level 3 | Other investments | Market comparables | Revenue multiples | Maximum |  |
Unobservable inputs |  |
Other investments, Input | 9.0 | 7.0
Fair value hierarchy Level 3 | Other investments | Market comparables | Revenue multiples | Weighted average input |  |
Unobservable inputs |  |
Other investments, Input | 7.0 | 4.1
Fair value hierarchy Level 3 | Other investments | Discounted cash flow, real estate | Discount rate |  |
Unobservable inputs |  |
Other investments, Input | 0.068 |
Fair value hierarchy Level 3 | Other investments | Discounted cash flow, real estate | Discount rate | Weighted average input |  |
Unobservable inputs |  |
Other investments, Input | 0.068 |
Fair value hierarchy Level 3 | Other investments | Discounted cash flow, real estate | Terminal capitalization rate |  |
Unobservable inputs |  |
Other investments, Input | 0.053 |
Fair value hierarchy Level 3 | Other investments | Discounted cash flow, real estate | Terminal capitalization rate | Weighted average input |  |
Unobservable inputs |  |
Other investments, Input | 0.053 |
Fair value hierarchy Level 3 | Other investments | Discounted cash flow, real estate | Average market rent growth rate |  |
Unobservable inputs |  |
Other investments, Input | 0.024 |
Fair value hierarchy Level 3 | Other investments | Discounted cash flow, real estate | Average market rent growth rate | Weighted average input |  |
Unobservable inputs |  |
Other investments, Input | 0.024 |
Fair value hierarchy Level 3 | Other investments | Discounted cash flow, real estate debt | Credit spread rate |  |
Unobservable inputs |  |
Other investments, Input | 0.039 |
Fair value hierarchy Level 3 | Other investments | Discounted cash flow, real estate debt | Credit spread rate | Weighted average input |  |
Unobservable inputs |  |
Other investments, Input | 0.039 |
Fair value hierarchy Level 3 | Other investments | Discounted cash flow, real estate debt | Loan to value |  |
Unobservable inputs |  |
Other investments, Input | 0.539 |
Fair value hierarchy Level 3 | Other investments | Discounted cash flow, real estate debt | Loan to value | Weighted average input |  |
Unobservable inputs |  |
Other investments, Input | 0.539 |
Fair value hierarchy Level 3 | Separate account assets |  |
Unobservable inputs |  |
Assets measured at fair value | $ | $ 8,854.7 | $ 8,966.2
Fair value hierarchy Level 3 | Separate account assets | Discounted cash flow, mortgage loans | Discount rate |  |
Unobservable inputs |  |
Separate account assets, Input | 0.014 | 0.028
Fair value hierarchy Level 3 | Separate account assets | Discounted cash flow, mortgage loans | Discount rate | Weighted average input |  |
Unobservable inputs |  |
Separate account assets, Input | 0.014 | 0.028
Fair value hierarchy Level 3 | Separate account assets | Discounted cash flow, mortgage loans | Illiquidity premium |  |
Unobservable inputs |  |
Separate account assets, Input | 0.0060 | 0.0060
Fair value hierarchy Level 3 | Separate account assets | Discounted cash flow, mortgage loans | Illiquidity premium | Weighted average input |  |
Unobservable inputs |  |
Separate account assets, Input | 0.0060 | 0.0060
Fair value hierarchy Level 3 | Separate account assets | Discounted cash flow, mortgage loans | Credit spread rate |  |
Unobservable inputs |  |
Separate account assets, Input | 0.0129 | 0.0120
Fair value hierarchy Level 3 | Separate account assets | Discounted cash flow, mortgage loans | Credit spread rate | Weighted average input |  |
Unobservable inputs |  |
Separate account assets, Input | 0.0129 | 0.0120
Fair value hierarchy Level 3 | Separate account assets | Discounted cash flow, real estate | Discount rate | Minimum |  |
Unobservable inputs |  |
Separate account assets, Input | 0.056 | 0.055
Fair value hierarchy Level 3 | Separate account assets | Discounted cash flow, real estate | Discount rate | Maximum |  |
Unobservable inputs |  |
Separate account assets, Input | 0.118 | 0.118
Fair value hierarchy Level 3 | Separate account assets | Discounted cash flow, real estate | Discount rate | Weighted average input |  |
Unobservable inputs |  |
Separate account assets, Input | 0.066 | 0.067
Fair value hierarchy Level 3 | Separate account assets | Discounted cash flow, real estate | Terminal capitalization rate | Minimum |  |
Unobservable inputs |  |
Separate account assets, Input | 0.045 | 0.045
Fair value hierarchy Level 3 | Separate account assets | Discounted cash flow, real estate | Terminal capitalization rate | Maximum |  |
Unobservable inputs |  |
Separate account assets, Input | 0.093 | 0.093
Fair value hierarchy Level 3 | Separate account assets | Discounted cash flow, real estate | Terminal capitalization rate | Weighted average input |  |
Unobservable inputs |  |
Separate account assets, Input | 0.056 | 0.057
Fair value hierarchy Level 3 | Separate account assets | Discounted cash flow, real estate | Average market rent growth rate | Minimum |  |
Unobservable inputs |  |
Separate account assets, Input | 0.015 | 0.020
Fair value hierarchy Level 3 | Separate account assets | Discounted cash flow, real estate | Average market rent growth rate | Maximum |  |
Unobservable inputs |  |
Separate account assets, Input | 0.046 | 0.047
Fair value hierarchy Level 3 | Separate account assets | Discounted cash flow, real estate | Average market rent growth rate | Weighted average input |  |
Unobservable inputs |  |
Separate account assets, Input | 0.028 | 0.030
Fair value hierarchy Level 3 | Separate account assets | Discounted cash flow, real estate debt | Loan to value | Minimum |  |
Unobservable inputs |  |
Separate account assets, Input | 0.074 | 0.080
Fair value hierarchy Level 3 | Separate account assets | Discounted cash flow, real estate debt | Loan to value | Maximum |  |
Unobservable inputs |  |
Separate account assets, Input | 0.802 | 0.804
Fair value hierarchy Level 3 | Separate account assets | Discounted cash flow, real estate debt | Loan to value | Weighted average input |  |
Unobservable inputs |  |
Separate account assets, Input | 0.470 | 0.459
Fair value hierarchy Level 3 | Separate account assets | Discounted cash flow, real estate debt | Market interest rate | Minimum |  |
Unobservable inputs |  |
Separate account assets, Input | 0.020 | 0.032
Fair value hierarchy Level 3 | Separate account assets | Discounted cash flow, real estate debt | Market interest rate | Maximum |  |
Unobservable inputs |  |
Separate account assets, Input | 0.059 | 0.058
Fair value hierarchy Level 3 | Separate account assets | Discounted cash flow, real estate debt | Market interest rate | Weighted average input |  |
Unobservable inputs |  |
Separate account assets, Input | 0.035 | 0.036

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