Investments (Details) - Fixed Maturities - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Investment disclosure details
Fixed maturities, amortized cost	$ 77,380	$ 74,751
Allowance for expected credit losses	3	3
Gross unrealized gains	135	3,356
Gross unrealized losses	6,352	294
Fixed maturities, at fair value	71,160	77,810
U.S. Treasury securities and obligations of U.S. government and government agencies and authorities [Member]
Investment disclosure details
Fixed maturities, amortized cost	5,798	3,574
Allowance for expected credit losses	0	0
Gross unrealized gains	3	20
Gross unrealized losses	363	32
Fixed maturities, at fair value	5,438	3,562
Obligations of U.S. states, municipalities and political subdivisions [Member]
Investment disclosure details
Fixed maturities, amortized cost	34,118	34,925
Allowance for expected credit losses	0	0
Gross unrealized gains	82	2,012
Gross unrealized losses	2,821	75
Fixed maturities, at fair value	31,379	36,862
Obligations of U.S. states, municipalities and political subdivisions, local general obligation [Member]
Investment disclosure details
Fixed maturities, amortized cost	19,615	18,668
Allowance for expected credit losses	0	0
Gross unrealized gains	33	1,045
Gross unrealized losses	1,825	46
Fixed maturities, at fair value	17,823	19,667
Obligations of U.S. states, municipalities and political subdivisions, revenue [Member]
Investment disclosure details
Fixed maturities, amortized cost	11,076	11,274
Allowance for expected credit losses	0	0
Gross unrealized gains	29	693
Gross unrealized losses	907	27
Fixed maturities, at fair value	10,198	11,940
Obligations of U.S. states, municipalities and political subdivisions, state general obligation [Member]
Investment disclosure details
Fixed maturities, amortized cost	1,104	1,158
Allowance for expected credit losses	0	0
Gross unrealized gains	3	67
Gross unrealized losses	88	2
Fixed maturities, at fair value	1,019	1,223
Obligations of U.S. states, municipalities and political subdivisions, pre-refunded [Member]
Investment disclosure details
Fixed maturities, amortized cost	2,323	3,825
Allowance for expected credit losses	0	0
Gross unrealized gains	17	207
Gross unrealized losses	1	0
Fixed maturities, at fair value	2,339	4,032
Debt securities issued by foreign governments [Member]
Investment disclosure details
Fixed maturities, amortized cost	1,049	1,041
Allowance for expected credit losses	0	0
Gross unrealized gains	0	7
Gross unrealized losses	55	7
Fixed maturities, at fair value	994	1,041
Mortgage-backed securities, collateralized mortgage obligations and pass-through securities [Member]
Investment disclosure details
Fixed maturities, amortized cost	2,178	1,754
Allowance for expected credit losses	0	0
Gross unrealized gains	13	68
Gross unrealized losses	200	5
Fixed maturities, at fair value	1,991	1,817
Corporate and all other bonds [Member]
Investment disclosure details
Fixed maturities, amortized cost	34,237	33,457
Allowance for expected credit losses	3	3	$ 2
Gross unrealized gains	37	1,249
Gross unrealized losses	2,913	175
Fixed maturities, at fair value	$ 31,358	$ 34,528

Amount, before tax, of unrealized gain in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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