The reserve to cover probable credit losses related to specifically identified fixed maturity real estate loans as well as probable credit losses inherent in the remainder of that loan portfolio.

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Investments - Mortgage loans amortized cost by debt service coverage ratio distribution and year of origination (Details) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Debt and Equity Securities, FV-NI [Line Items]
Mortgage loans, net	$ 902	$ 746
Mortgage loans
Debt and Equity Securities, FV-NI [Line Items]
Amortized cost before allowance	916	754
Allowance	(14)	(8)
Mortgage loans, net	902	746
Mortgage loans \| 2016 and prior
Debt and Equity Securities, FV-NI [Line Items]
Amortized cost before allowance	283
Mortgage loans \| 2017
Debt and Equity Securities, FV-NI [Line Items]
Amortized cost before allowance	81
Mortgage loans \| 2018
Debt and Equity Securities, FV-NI [Line Items]
Amortized cost before allowance	156
Mortgage loans \| 2019
Debt and Equity Securities, FV-NI [Line Items]
Amortized cost before allowance	319
Mortgage loans \| 2020
Debt and Equity Securities, FV-NI [Line Items]
Amortized cost before allowance	77
Mortgage loans \| Current
Debt and Equity Securities, FV-NI [Line Items]
Amortized cost before allowance	0
Below 1.0 \| Mortgage loans
Debt and Equity Securities, FV-NI [Line Items]
Amortized cost before allowance	15	0
Below 1.0 \| Mortgage loans \| 2016 and prior
Debt and Equity Securities, FV-NI [Line Items]
Amortized cost before allowance	15
Below 1.0 \| Mortgage loans \| 2017
Debt and Equity Securities, FV-NI [Line Items]
Amortized cost before allowance	0
Below 1.0 \| Mortgage loans \| 2018
Debt and Equity Securities, FV-NI [Line Items]
Amortized cost before allowance	0
Below 1.0 \| Mortgage loans \| 2019
Debt and Equity Securities, FV-NI [Line Items]
Amortized cost before allowance	0
Below 1.0 \| Mortgage loans \| 2020
Debt and Equity Securities, FV-NI [Line Items]
Amortized cost before allowance	0
Below 1.0 \| Mortgage loans \| Current
Debt and Equity Securities, FV-NI [Line Items]
Amortized cost before allowance	0
1.0 - 1.25 \| Mortgage loans
Debt and Equity Securities, FV-NI [Line Items]
Amortized cost before allowance	75	46
1.0 - 1.25 \| Mortgage loans \| 2016 and prior
Debt and Equity Securities, FV-NI [Line Items]
Amortized cost before allowance	29
1.0 - 1.25 \| Mortgage loans \| 2017
Debt and Equity Securities, FV-NI [Line Items]
Amortized cost before allowance	0
1.0 - 1.25 \| Mortgage loans \| 2018
Debt and Equity Securities, FV-NI [Line Items]
Amortized cost before allowance	13
1.0 - 1.25 \| Mortgage loans \| 2019
Debt and Equity Securities, FV-NI [Line Items]
Amortized cost before allowance	23
1.0 - 1.25 \| Mortgage loans \| 2020
Debt and Equity Securities, FV-NI [Line Items]
Amortized cost before allowance	10
1.0 - 1.25 \| Mortgage loans \| Current
Debt and Equity Securities, FV-NI [Line Items]
Amortized cost before allowance	0
1.26 - 1.50 \| Mortgage loans
Debt and Equity Securities, FV-NI [Line Items]
Amortized cost before allowance	295	201
1.26 - 1.50 \| Mortgage loans \| 2016 and prior
Debt and Equity Securities, FV-NI [Line Items]
Amortized cost before allowance	105
1.26 - 1.50 \| Mortgage loans \| 2017
Debt and Equity Securities, FV-NI [Line Items]
Amortized cost before allowance	36
1.26 - 1.50 \| Mortgage loans \| 2018
Debt and Equity Securities, FV-NI [Line Items]
Amortized cost before allowance	24
1.26 - 1.50 \| Mortgage loans \| 2019
Debt and Equity Securities, FV-NI [Line Items]
Amortized cost before allowance	130
1.26 - 1.50 \| Mortgage loans \| 2020
Debt and Equity Securities, FV-NI [Line Items]
Amortized cost before allowance	0
1.26 - 1.50 \| Mortgage loans \| Current
Debt and Equity Securities, FV-NI [Line Items]
Amortized cost before allowance	0
Above 1.50 \| Mortgage loans
Debt and Equity Securities, FV-NI [Line Items]
Amortized cost before allowance	531	$ 507
Above 1.50 \| Mortgage loans \| 2016 and prior
Debt and Equity Securities, FV-NI [Line Items]
Amortized cost before allowance	134
Above 1.50 \| Mortgage loans \| 2017
Debt and Equity Securities, FV-NI [Line Items]
Amortized cost before allowance	45
Above 1.50 \| Mortgage loans \| 2018
Debt and Equity Securities, FV-NI [Line Items]
Amortized cost before allowance	119
Above 1.50 \| Mortgage loans \| 2019
Debt and Equity Securities, FV-NI [Line Items]
Amortized cost before allowance	166
Above 1.50 \| Mortgage loans \| 2020
Debt and Equity Securities, FV-NI [Line Items]
Amortized cost before allowance	67
Above 1.50 \| Mortgage loans \| Current
Debt and Equity Securities, FV-NI [Line Items]
Amortized cost before allowance	$ 0