Variable Interest Entities Variable Interest Entity - Change in Fair Value of Assets and Liabilities (Details) $ in Millions	3 Months Ended		12 Months Ended
	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)
Deconsolidated VIE Assets	$ 0		$ 0
Fixed income securities, amortized cost	2,807	$ 3,187	2,807	$ 3,187
Long-term debt	2,739	2,822	2,739	2,822
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	149	132	149	132
Variable Interest Entity Change in Fair Value of Assets and Liabilities			(1)	13	$ 3
Other Comprehensive Income (Loss), Financial Liability, Fair Value Option, Reclassification Adjustment from AOCI for Derecognition, before Tax					(1)
Realized Investment Gains (Losses)	2	9	22	81	108
Variable Interest Entity, Initial Consolidation, Gain (Loss)			0	15	0
Variable Interest Entities Deconsolidation Gain Loss			0	(2)	2
Variable Interest Entity, Measure of Activity, Income or Loss before Tax			5	$ 38	$ 3
Variable Interest Entity, Consolidated, Carrying Amount, Assets	292		292
Variable Interest Entity, Consolidated, Carrying Amount, Liabilities	364		364
Deconsolidated VIE Liabilities	0		$ 0
Consolidated Entities [Member]
Number of DeConsolidated Variable Interest Entities			1	1	4
Variable Interest Entities [Member]
Loans, Unpaid principal balance	2,546	2,618	$ 2,546	$ 2,618
Long-term debt, Unpaid principal balance	3,769	3,800	3,769	3,800
Other Comprehensive Income (Loss), Financial Liability, Fair Value Option, Reclassification Adjustment from AOCI for Derecognition, before Tax			(3)	14	$ 2
Variable Interest Entity, Not Primary Beneficiary, Aggregated Disclosure [Member]
Other Comprehensive Income (Loss), Financial Liability, Fair Value Option, Reclassification Adjustment from AOCI for Derecognition, before Tax			(1)	0
Variable Interest Entity [Member]
Long-term debt	$ 4,493	$ 4,554	4,493	4,554
Interest Expense, Long-term Debt			(6)	(11)	0
Other Expenses			0	(1)	0
Variable Interest Entity [Member] | Available-for-sale Securities [Member]
Gross Investment Income, Operating			7	10	0
Realized Investment Gains (Losses)			$ 8	$ 13	$ 0