Investments - Loans by Loan to Value (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Mar. 31, 2023	Sep. 30, 2022	Dec. 31, 2022
Schedule of Loans by Loan to Value Ratio [Line Items]
Financing Receivable, before Allowance for Credit Loss	$ 4,148		$ 4,227
Targeted maximum amount of mortgage loans lended, percent of estimated fair value of underlying real estate	75.00%
Benchmark loan to value ratio, greater than indicates unpaid loan amount exceeds underlying collateral	100.00%
0% - 50%
Schedule of Loans by Loan to Value Ratio [Line Items]
Financing Receivable, before Allowance for Credit Loss	$ 2,645		2,651
Loans Receivable, Loan to Value Ratio, Minimum	0.00%	0.00%
Loans Receivable, Loan to Value Ratio, Maximum	50.00%	50.00%
50% - 60%
Schedule of Loans by Loan to Value Ratio [Line Items]
Financing Receivable, before Allowance for Credit Loss	$ 1,138		1,187
Loans Receivable, Loan to Value Ratio, Minimum	50.00%	50.00%
Loans Receivable, Loan to Value Ratio, Maximum	60.00%	60.00%
60% - 70%
Schedule of Loans by Loan to Value Ratio [Line Items]
Financing Receivable, before Allowance for Credit Loss	$ 355		369
Loans Receivable, Loan to Value Ratio, Minimum	60.00%	60.00%
Loans Receivable, Loan to Value Ratio, Maximum	70.00%	70.00%
70% - 80%
Schedule of Loans by Loan to Value Ratio [Line Items]
Financing Receivable, before Allowance for Credit Loss	$ 10		20
Loans Receivable, Loan to Value Ratio, Minimum	70.00%	70.00%
Loans Receivable, Loan to Value Ratio, Maximum	80.00%	80.00%
>80% and above
Schedule of Loans by Loan to Value Ratio [Line Items]
Financing Receivable, before Allowance for Credit Loss	$ 0		0
Loans Receivable, Loan to Value Ratio, Minimum	80.00%	80.00%
Year of Origination 2020
Schedule of Loans by Loan to Value Ratio [Line Items]
Financing Receivable, before Allowance for Credit Loss	$ 284		302
Year of Origination 2020 | 0% - 50%
Schedule of Loans by Loan to Value Ratio [Line Items]
Financing Receivable, before Allowance for Credit Loss	126		98
Year of Origination 2020 | 50% - 60%
Schedule of Loans by Loan to Value Ratio [Line Items]
Financing Receivable, before Allowance for Credit Loss	134		170
Year of Origination 2020 | 60% - 70%
Schedule of Loans by Loan to Value Ratio [Line Items]
Financing Receivable, before Allowance for Credit Loss	14		24
Year of Origination 2020 | 70% - 80%
Schedule of Loans by Loan to Value Ratio [Line Items]
Financing Receivable, before Allowance for Credit Loss	10		10
Year of Origination 2020 | >80% and above
Schedule of Loans by Loan to Value Ratio [Line Items]
Financing Receivable, before Allowance for Credit Loss	0		0
Year of Origination 2019
Schedule of Loans by Loan to Value Ratio [Line Items]
Financing Receivable, before Allowance for Credit Loss	257		259
Year of Origination 2019 | 0% - 50%
Schedule of Loans by Loan to Value Ratio [Line Items]
Financing Receivable, before Allowance for Credit Loss	166		167
Year of Origination 2019 | 50% - 60%
Schedule of Loans by Loan to Value Ratio [Line Items]
Financing Receivable, before Allowance for Credit Loss	71		72
Year of Origination 2019 | 60% - 70%
Schedule of Loans by Loan to Value Ratio [Line Items]
Financing Receivable, before Allowance for Credit Loss	20		20
Year of Origination 2019 | 70% - 80%
Schedule of Loans by Loan to Value Ratio [Line Items]
Financing Receivable, before Allowance for Credit Loss	0		0
Year of Origination 2019 | >80% and above
Schedule of Loans by Loan to Value Ratio [Line Items]
Financing Receivable, before Allowance for Credit Loss	0		0
Year of Origination 2018
Schedule of Loans by Loan to Value Ratio [Line Items]
Financing Receivable, before Allowance for Credit Loss	158		160
Year of Origination 2018 | 0% - 50%
Schedule of Loans by Loan to Value Ratio [Line Items]
Financing Receivable, before Allowance for Credit Loss	121		123
Year of Origination 2018 | 50% - 60%
Schedule of Loans by Loan to Value Ratio [Line Items]
Financing Receivable, before Allowance for Credit Loss	34		34
Year of Origination 2018 | 60% - 70%
Schedule of Loans by Loan to Value Ratio [Line Items]
Financing Receivable, before Allowance for Credit Loss	3		3
Year of Origination 2018 | 70% - 80%
Schedule of Loans by Loan to Value Ratio [Line Items]
Financing Receivable, before Allowance for Credit Loss	0		0
Year of Origination 2018 | >80% and above
Schedule of Loans by Loan to Value Ratio [Line Items]
Financing Receivable, before Allowance for Credit Loss	0		0
Year of Origination 2017
Schedule of Loans by Loan to Value Ratio [Line Items]
Financing Receivable, before Allowance for Credit Loss	2,221		2,285
Year of Origination 2017 | 0% - 50%
Schedule of Loans by Loan to Value Ratio [Line Items]
Financing Receivable, before Allowance for Credit Loss	1,805		1,866
Year of Origination 2017 | 50% - 60%
Schedule of Loans by Loan to Value Ratio [Line Items]
Financing Receivable, before Allowance for Credit Loss	397		399
Year of Origination 2017 | 60% - 70%
Schedule of Loans by Loan to Value Ratio [Line Items]
Financing Receivable, before Allowance for Credit Loss	19		20
Year of Origination 2017 | 70% - 80%
Schedule of Loans by Loan to Value Ratio [Line Items]
Financing Receivable, before Allowance for Credit Loss	0		0
Year of Origination 2017 | >80% and above
Schedule of Loans by Loan to Value Ratio [Line Items]
Financing Receivable, before Allowance for Credit Loss	0		0
Year of Origination 2021
Schedule of Loans by Loan to Value Ratio [Line Items]
Financing Receivable, before Allowance for Credit Loss	625		665
Year of Origination 2021 | 0% - 50%
Schedule of Loans by Loan to Value Ratio [Line Items]
Financing Receivable, before Allowance for Credit Loss	183		187
Year of Origination 2021 | 50% - 60%
Schedule of Loans by Loan to Value Ratio [Line Items]
Financing Receivable, before Allowance for Credit Loss	206		229
Year of Origination 2021 | 60% - 70%
Schedule of Loans by Loan to Value Ratio [Line Items]
Financing Receivable, before Allowance for Credit Loss	236		239
Year of Origination 2021 | 70% - 80%
Schedule of Loans by Loan to Value Ratio [Line Items]
Financing Receivable, before Allowance for Credit Loss	0		10
Year of Origination 2021 | >80% and above
Schedule of Loans by Loan to Value Ratio [Line Items]
Financing Receivable, before Allowance for Credit Loss	0		0
Year of Origination 2022
Schedule of Loans by Loan to Value Ratio [Line Items]
Financing Receivable, before Allowance for Credit Loss	565		556
Year of Origination 2022 | 0% - 50%
Schedule of Loans by Loan to Value Ratio [Line Items]
Financing Receivable, before Allowance for Credit Loss	206		210
Year of Origination 2022 | 50% - 60%
Schedule of Loans by Loan to Value Ratio [Line Items]
Financing Receivable, before Allowance for Credit Loss	296		283
Year of Origination 2022 | 60% - 70%
Schedule of Loans by Loan to Value Ratio [Line Items]
Financing Receivable, before Allowance for Credit Loss	63		63
Year of Origination 2022 | 70% - 80%
Schedule of Loans by Loan to Value Ratio [Line Items]
Financing Receivable, before Allowance for Credit Loss	0		0
Year of Origination 2022 | >80% and above
Schedule of Loans by Loan to Value Ratio [Line Items]
Financing Receivable, before Allowance for Credit Loss	0		$ 0
Year of Origination 2023
Schedule of Loans by Loan to Value Ratio [Line Items]
Financing Receivable, before Allowance for Credit Loss	38
Year of Origination 2023 | 0% - 50%
Schedule of Loans by Loan to Value Ratio [Line Items]
Financing Receivable, before Allowance for Credit Loss	38
Year of Origination 2023 | 50% - 60%
Schedule of Loans by Loan to Value Ratio [Line Items]
Financing Receivable, before Allowance for Credit Loss	0
Year of Origination 2023 | 60% - 70%
Schedule of Loans by Loan to Value Ratio [Line Items]
Financing Receivable, before Allowance for Credit Loss	0
Year of Origination 2023 | 70% - 80%
Schedule of Loans by Loan to Value Ratio [Line Items]
Financing Receivable, before Allowance for Credit Loss	0
Year of Origination 2023 | >80% and above
Schedule of Loans by Loan to Value Ratio [Line Items]
Financing Receivable, before Allowance for Credit Loss	$ 0