Fair Value Measurements - Other Financial Instruments (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	$ 224	$ 128
Other investments	43	40
Assets held in separate accounts	78,713	67,323
Derivatives liabilities	285	99
Carrying Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fixed maturities including securities pledged, Fair Value	27,460	25,034
Equity securities, available-for-sale	80	57
Cash, Cash Equivalents, and Short-term Investments	1,429	1,207
Derivative assets	224	128
Short-term loan to affiliate	69	0
Other investments	43	40
Assets held in separate accounts	78,713	67,323
Deposit liabilities	76	77
Derivatives liabilities	285	99
Short-term Debt	1	1
Long-term debt, fair value	4	4
Carrying Value | Embedded derivative on reinsurance
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Embedded derivative on reinsurance	23	(80)
Carrying Value | Funding agreements without fixed maturities and deferred annuities(1)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Liabilities	26,337	26,068
Carrying Value | Funding agreements with a Fixed Maturity [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Liabilities	877	658
Carrying Value | Supplementary Contracts and Immediate Annuities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Liabilities	312	333
Carrying Value | FIA
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Liabilities	11	11
Carrying Value | Stabilizer and MCGs
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Liabilities	22	4
Carrying Value | Mortgage loans on real estate
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	4,664	4,918
Carrying Value | Policy loans
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	205	210
Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fixed maturities including securities pledged, Fair Value	27,460	25,034
Equity securities, available-for-sale	80	57
Cash, Cash Equivalents, and Short-term Investments	1,429	1,207
Derivative assets	224	128
Short-term loan to affiliate	69	0
Other investments	43	40
Assets held in separate accounts	78,713	67,323
Deposit liabilities	152	122
Derivatives liabilities	285	99
Short-term Debt	1	1
Long-term debt, fair value	4	4
Fair Value | Embedded derivative on reinsurance
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Embedded derivative on reinsurance	23	(80)
Fair Value | Funding agreements without fixed maturities and deferred annuities(1)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Liabilities	32,697	29,108
Fair Value | Funding agreements with a Fixed Maturity [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Liabilities	876	652
Fair Value | Supplementary Contracts and Immediate Annuities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Liabilities	384	354
Fair Value | FIA
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Liabilities	11	11
Fair Value | Stabilizer and MCGs
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Liabilities	22	4
Fair Value | Mortgage loans on real estate
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	4,912	4,983
Fair Value | Policy loans
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	$ 205	$ 210