Amount of obligation to return cash borrowed from swap collateral.

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Amount of right to receive cash collateral under master netting arrangements that have not been offset against derivative liabilities.

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Fair value of the assets less the liabilities of a derivative or group of derivatives.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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The effective portion of net gain (loss) reclassified from accumulated other comprehensive income into income on derivative instruments designated and qualifying as hedging instruments.

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Nominal or face amount used to calculate payment on derivative.

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Number of interest rate derivative instruments held by the entity at the reporting date.

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Derivatives - Narrative (Details)	3 Months Ended			6 Months Ended
Derivatives - Narrative (Details)	Jun. 30, 2020 USD ($) swap	Mar. 31, 2020 USD ($) swap	Jun. 30, 2019 USD ($)	Jun. 30, 2020 USD ($) swap	Jun. 30, 2019 USD ($)	Dec. 31, 2019 USD ($)
Derivative Instruments, Gain (Loss) [Line Items]
Carrying value of collateral received to support purchased call options	$ 284,000,000			$ 284,000,000		$ 577,000,000
Cash Flow Hedges \| Designated as Hedging Instrument \| Interest rate swaps
Derivative Instruments, Gain (Loss) [Line Items]
Number of interest rate swaps designated and qualifying as a cash flow hedges \| swap	9			9
Derivative, notional amount	$ 1,680,000,000			$ 1,680,000,000		1,980,000,000
Gain (loss) reclassified from AOCI into net investment income	11,000,000		$ 1,000,000	23,000,000	$ (1,000,000)
Collateral payable related to interest rate swaps	13,000,000			13,000,000
Collateral receivable related to interest rate swaps						20,000,000
Other assets \| Cash Flow Hedges \| Designated as Hedging Instrument \| Interest rate swaps
Derivative Instruments, Gain (Loss) [Line Items]
Net derivatives, at fair value	124,000,000			124,000,000		50,000,000
Other liabilities \| Cash Flow Hedges \| Designated as Hedging Instrument \| Interest rate swaps
Derivative Instruments, Gain (Loss) [Line Items]
Net derivatives, at fair value	0			0		$ (5,000,000)
Contract termination \| Cash Flow Hedges \| Interest rate swaps
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, notional amount	$ 166,000,000	$ 83,000,000		166,000,000
Number of interest rate derivatives terminated \| swap	2	1
Facility closing \| Cash Flow Hedges \| Interest rate swaps
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, notional amount	$ 44,000,000			$ 44,000,000
Number of interest rate derivatives terminated \| swap	1