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Investments - Bank loans amortized cost by credit quality and year of origination (Details) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Schedule of Available for Sale Securities
Mortgage loans, net	$ 902	$ 746
Bank loans, net
Schedule of Available for Sale Securities
Amortized cost before allowance	1,309	823
Allowance	(49)	(51)
Mortgage loans, net	1,260	772
BBB \| Bank loans, net
Schedule of Available for Sale Securities
Amortized cost before allowance	60	38
BB \| Bank loans, net
Schedule of Available for Sale Securities
Amortized cost before allowance	311	168
B \| Bank loans, net
Schedule of Available for Sale Securities
Amortized cost before allowance	772	456
CCC and below \| Bank loans, net
Schedule of Available for Sale Securities
Amortized cost before allowance	166	$ 161
2016 and prior \| Bank loans, net
Schedule of Available for Sale Securities
Amortized cost before allowance	33
2016 and prior \| BBB \| Bank loans, net
Schedule of Available for Sale Securities
Amortized cost before allowance	0
2016 and prior \| BB \| Bank loans, net
Schedule of Available for Sale Securities
Amortized cost before allowance	9
2016 and prior \| B \| Bank loans, net
Schedule of Available for Sale Securities
Amortized cost before allowance	13
2016 and prior \| CCC and below \| Bank loans, net
Schedule of Available for Sale Securities
Amortized cost before allowance	11
2017 \| Bank loans, net
Schedule of Available for Sale Securities
Amortized cost before allowance	123
2017 \| BBB \| Bank loans, net
Schedule of Available for Sale Securities
Amortized cost before allowance	5
2017 \| BB \| Bank loans, net
Schedule of Available for Sale Securities
Amortized cost before allowance	22
2017 \| B \| Bank loans, net
Schedule of Available for Sale Securities
Amortized cost before allowance	68
2017 \| CCC and below \| Bank loans, net
Schedule of Available for Sale Securities
Amortized cost before allowance	28
2018 \| Bank loans, net
Schedule of Available for Sale Securities
Amortized cost before allowance	155
2018 \| BBB \| Bank loans, net
Schedule of Available for Sale Securities
Amortized cost before allowance	7
2018 \| BB \| Bank loans, net
Schedule of Available for Sale Securities
Amortized cost before allowance	30
2018 \| B \| Bank loans, net
Schedule of Available for Sale Securities
Amortized cost before allowance	86
2018 \| CCC and below \| Bank loans, net
Schedule of Available for Sale Securities
Amortized cost before allowance	32
2019 \| Bank loans, net
Schedule of Available for Sale Securities
Amortized cost before allowance	185
2019 \| BBB \| Bank loans, net
Schedule of Available for Sale Securities
Amortized cost before allowance	11
2019 \| BB \| Bank loans, net
Schedule of Available for Sale Securities
Amortized cost before allowance	42
2019 \| B \| Bank loans, net
Schedule of Available for Sale Securities
Amortized cost before allowance	77
2019 \| CCC and below \| Bank loans, net
Schedule of Available for Sale Securities
Amortized cost before allowance	55
2020 \| Bank loans, net
Schedule of Available for Sale Securities
Amortized cost before allowance	210
2020 \| BBB \| Bank loans, net
Schedule of Available for Sale Securities
Amortized cost before allowance	8
2020 \| BB \| Bank loans, net
Schedule of Available for Sale Securities
Amortized cost before allowance	36
2020 \| B \| Bank loans, net
Schedule of Available for Sale Securities
Amortized cost before allowance	139
2020 \| CCC and below \| Bank loans, net
Schedule of Available for Sale Securities
Amortized cost before allowance	27
Current \| Bank loans, net
Schedule of Available for Sale Securities
Amortized cost before allowance	603
Current \| BBB \| Bank loans, net
Schedule of Available for Sale Securities
Amortized cost before allowance	29
Current \| BB \| Bank loans, net
Schedule of Available for Sale Securities
Amortized cost before allowance	172
Current \| B \| Bank loans, net
Schedule of Available for Sale Securities
Amortized cost before allowance	389
Current \| CCC and below \| Bank loans, net
Schedule of Available for Sale Securities
Amortized cost before allowance	$ 13