Investments - Commercial Mortgage Loans LTV & DSCR (Details) $ in Millions	12 Months Ended
	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)
Schedule of Investments [Line Items]
Number of loans held-for-sale	0	0
Financing Receivable, Modifications, Number of Contracts	0	0
LTV ratio	55.00%
LTV ratio at origination	59.00%
Commercial Loan [Member]
Schedule of Investments [Line Items]
Financing Receivable, Individually Evaluated for Impairment	$ 0
Avg. Debt-Service Coverage Ratio	2.60	2.59
Financing Receivable, before Allowance for Credit Loss	$ 6,138	$ 6,036
Financing Receivable, Allowance for Credit Loss	$ 51	$ 36	$ 29	$ 38
Commercial Loan [Member] | LTV Greater Than 80 Percent
Schedule of Investments [Line Items]
Avg. Debt-Service Coverage Ratio	1.29	1.40
Commercial Loan [Member] | 65% - 80%
Schedule of Investments [Line Items]
Avg. Debt-Service Coverage Ratio	2.25	1.91
Commercial Loan [Member] | Less than 65%
Schedule of Investments [Line Items]
Avg. Debt-Service Coverage Ratio	2.72	2.65
Amortized Cost [Member] | Commercial Loan [Member]
Schedule of Investments [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	$ 400	$ 855
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	929	1,534
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	1,600	706
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	622	780
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	777	545
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	1,810	1,616
Financing Receivable, before Allowance for Credit Loss	6,138	6,036
Amortized Cost [Member] | Commercial Loan [Member] | LTV Greater Than 80 Percent
Schedule of Investments [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	0	0
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	16	0
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	38	0
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	0	0
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	0	0
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	105	23
Financing Receivable, before Allowance for Credit Loss	159	23
Amortized Cost [Member] | Commercial Loan [Member] | 65% - 80%
Schedule of Investments [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	0	16
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	189	59
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	457	43
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	95	100
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	98	108
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	252	117
Financing Receivable, before Allowance for Credit Loss	1,091	443
Amortized Cost [Member] | Commercial Loan [Member] | Less than 65%
Schedule of Investments [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	400	839
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	724	1,475
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	1,105	663
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	527	680
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	679	437
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	1,453	1,476
Financing Receivable, before Allowance for Credit Loss	$ 4,888	$ 5,570
Originated in Current Fiscal Year [Member] | Commercial Loan [Member]
Schedule of Investments [Line Items]
Avg. Debt-Service Coverage Ratio	1.47	2.42
Originated in Current Fiscal Year [Member] | Commercial Loan [Member] | LTV Greater Than 80 Percent
Schedule of Investments [Line Items]
Avg. Debt-Service Coverage Ratio	0	0
Originated in Current Fiscal Year [Member] | Commercial Loan [Member] | 65% - 80%
Schedule of Investments [Line Items]
Avg. Debt-Service Coverage Ratio	0	2.02
Originated in Current Fiscal Year [Member] | Commercial Loan [Member] | Less than 65%
Schedule of Investments [Line Items]
Avg. Debt-Service Coverage Ratio	1.47	2.43
Originated in Fiscal Year before Latest Fiscal Year [Member] | Commercial Loan [Member]
Schedule of Investments [Line Items]
Avg. Debt-Service Coverage Ratio	2.60	2.78
Originated in Fiscal Year before Latest Fiscal Year [Member] | Commercial Loan [Member] | LTV Greater Than 80 Percent
Schedule of Investments [Line Items]
Avg. Debt-Service Coverage Ratio	1.09	0
Originated in Fiscal Year before Latest Fiscal Year [Member] | Commercial Loan [Member] | 65% - 80%
Schedule of Investments [Line Items]
Avg. Debt-Service Coverage Ratio	2.13	2.61
Originated in Fiscal Year before Latest Fiscal Year [Member] | Commercial Loan [Member] | Less than 65%
Schedule of Investments [Line Items]
Avg. Debt-Service Coverage Ratio	2.75	2.79
Originated Two Years before Latest Fiscal Year [Member] | Commercial Loan [Member]
Schedule of Investments [Line Items]
Avg. Debt-Service Coverage Ratio	2.78	3.01
Originated Two Years before Latest Fiscal Year [Member] | Commercial Loan [Member] | LTV Greater Than 80 Percent
Schedule of Investments [Line Items]
Avg. Debt-Service Coverage Ratio	1.05	0
Originated Two Years before Latest Fiscal Year [Member] | Commercial Loan [Member] | 65% - 80%
Schedule of Investments [Line Items]
Avg. Debt-Service Coverage Ratio	2.42	2.78
Originated Two Years before Latest Fiscal Year [Member] | Commercial Loan [Member] | Less than 65%
Schedule of Investments [Line Items]
Avg. Debt-Service Coverage Ratio	2.99	3.02
Originated Three Years before Latest Fiscal Year [Member] | Commercial Loan [Member]
Schedule of Investments [Line Items]
Avg. Debt-Service Coverage Ratio	3.00	2.66
Originated Three Years before Latest Fiscal Year [Member] | Commercial Loan [Member] | LTV Greater Than 80 Percent
Schedule of Investments [Line Items]
Avg. Debt-Service Coverage Ratio	0	0
Originated Three Years before Latest Fiscal Year [Member] | Commercial Loan [Member] | 65% - 80%
Schedule of Investments [Line Items]
Avg. Debt-Service Coverage Ratio	3.47	1.95
Originated Three Years before Latest Fiscal Year [Member] | Commercial Loan [Member] | Less than 65%
Schedule of Investments [Line Items]
Avg. Debt-Service Coverage Ratio	2.92	2.77
Originated Four Years before Latest Fiscal Year [Member] | Commercial Loan [Member]
Schedule of Investments [Line Items]
Avg. Debt-Service Coverage Ratio	2.76	1.99
Originated Four Years before Latest Fiscal Year [Member] | Commercial Loan [Member] | LTV Greater Than 80 Percent
Schedule of Investments [Line Items]
Avg. Debt-Service Coverage Ratio	0	0
Originated Four Years before Latest Fiscal Year [Member] | Commercial Loan [Member] | 65% - 80%
Schedule of Investments [Line Items]
Avg. Debt-Service Coverage Ratio	1.77	1.11
Originated Four Years before Latest Fiscal Year [Member] | Commercial Loan [Member] | Less than 65%
Schedule of Investments [Line Items]
Avg. Debt-Service Coverage Ratio	2.90	2.21
Originated Five or More Years before Latest Fiscal Year [Member] | Commercial Loan [Member]
Schedule of Investments [Line Items]
Avg. Debt-Service Coverage Ratio	2.47	2.48
Originated Five or More Years before Latest Fiscal Year [Member] | Commercial Loan [Member] | LTV Greater Than 80 Percent
Schedule of Investments [Line Items]
Avg. Debt-Service Coverage Ratio	1.41	1.40
Originated Five or More Years before Latest Fiscal Year [Member] | Commercial Loan [Member] | 65% - 80%
Schedule of Investments [Line Items]
Avg. Debt-Service Coverage Ratio	1.77	1.91
Originated Five or More Years before Latest Fiscal Year [Member] | Commercial Loan [Member] | Less than 65%
Schedule of Investments [Line Items]
Avg. Debt-Service Coverage Ratio	2.67	2.54