Derivatives - Cash Flow Hedges (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Net Investment Income	$ 593	$ 515
Interest Expense	50	50
Cash Flow Hedging | Designated as Hedging Instrument
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification and Tax	0	7
Cash Flow Hedging | Designated as Hedging Instrument | Net investment income | Reclassification out of Accumulated Other Comprehensive Income
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Gain (Loss) Reclassified from AOCI into Income (Effective Portion)	(4)	(6)
Cash Flow Hedging | Designated as Hedging Instrument | Interest expense | Reclassification out of Accumulated Other Comprehensive Income
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Gain (Loss) Reclassified from AOCI into Income (Effective Portion)	4	3
Interest rate swaps | Reclassification out of Accumulated Other Comprehensive Income | Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Net Investment Income	(7)	(8)
Interest Expense	4	3
Interest rate swaps | Cash Flow Hedging | Designated as Hedging Instrument
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification and Tax	(17)	11
Interest rate swaps | Cash Flow Hedging | Designated as Hedging Instrument | Net investment income | Reclassification out of Accumulated Other Comprehensive Income | Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Gain (Loss) Reclassified from AOCI into Income (Effective Portion)	(7)	(8)
Interest rate swaps | Cash Flow Hedging | Designated as Hedging Instrument | Interest expense | Reclassification out of Accumulated Other Comprehensive Income | Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Gain (Loss) Reclassified from AOCI into Income (Effective Portion)	4	3
Foreign currency swaps | Reclassification out of Accumulated Other Comprehensive Income | Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Net Investment Income	3	2
Foreign currency swaps | Cash Flow Hedging | Designated as Hedging Instrument
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification and Tax	17	(4)
Foreign currency swaps | Cash Flow Hedging | Designated as Hedging Instrument | Net investment income | Reclassification out of Accumulated Other Comprehensive Income | Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Gain (Loss) Reclassified from AOCI into Income (Effective Portion)	3	2
Foreign currency swaps | Cash Flow Hedging | Designated as Hedging Instrument | Interest expense | Reclassification out of Accumulated Other Comprehensive Income | Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Gain (Loss) Reclassified from AOCI into Income (Effective Portion)	$ 0	$ 0