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Derivatives - Narrative (Details) | 3 Months Ended | 12 Months Ended |
--- | --- | --- | ---
Sep. 30, 2019 USD ($) swap | Dec. 31, 2019 USD ($) swap | Dec. 31, 2018 USD ($) | Dec. 31, 2017 USD ($) | Jun. 30, 2019 USD ($)
Derivative Instruments, Gain (Loss) [Line Items] |  |  |  |  |
Carrying value of collateral received to support purchased call options |  | $ 577,000,000 | $ 103,000,000 |  |
Interest rate swaps | Cash Flow Hedges | Contract termination |  |  |  |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |  |  |  |
Derivative, Notional Amount | $ 78,000,000 | $ 100,000,000 |  |  | $ 138,000,000
Number of interest rate swaps terminated | swap |  | 2 |  |  |
Number of interest rate swaps expired | swap | 1 |  |  |  |
Not Designated as Hedging Instrument | Fixed-indexed and variable-indexed annuities (embedded derivative) | Annuity benefits |  |  |  |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |  |  |  |
The portion of the change in fair value of the embedded derivative related to the unlocking of actuarial assumptions |  | $ 181,000,000 | (44,000,000) | $ (25,000,000) |
Designated as Hedging Instrument | Interest rate swaps | Cash Flow Hedges |  |  |  |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |  |  |  |
Number of interest rate swaps designated and qualifying as a cash flow hedges | swap |  | 13 |  |  |
Derivative, Notional Amount |  | $ 1,980,000,000 | 2,350,000,000 |  |
Gain (loss) reclassified from AOCI into net investment income |  | 3,000,000 | (3,000,000) | $ 6,000,000 |
Collateral receivable supporting interest rate swaps |  | 20,000,000 | 135,000,000 |  |
Designated as Hedging Instrument | Interest rate swaps | Cash Flow Hedges | Other assets |  |  |  |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |  |  |  |
Net derivatives, at fair value |  | 50,000,000 | 16,000,000 |  |
Designated as Hedging Instrument | Interest rate swaps | Cash Flow Hedges | Other liabilities |  |  |  |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |  |  |  |
Net derivatives, at fair value |  | $ (5,000,000) | $ (46,000,000) |  |

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- Definition Number of interest rate derivative instruments terminated during the reporting period. + References No definition available. + Details
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- Definition The aggregate fair value of assets that are already posted, at the end of the reporting period, as collateral for derivative instruments with credit-risk-related contingent features. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4H -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5624258-113959 + Details
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- Definition Amount of right to receive cash collateral under master netting arrangements that have not been offset against derivative liabilities. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 20 -Section 55 -Paragraph 13 -URI http://asc.fasb.org/extlink&oid=99393222&loc=SL20226016-175313 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 8 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=109980867&loc=d3e41678-113959 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 20 -Section 50 -Paragraph 3 -Subparagraph (d)(2) -URI http://asc.fasb.org/extlink&oid=51824906&loc=SL20225862-175312 + Details
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