Investments (Details) - Investment Information, Debt Securities - USD ($)
$ in Millions |
3 Months Ended |
|
Mar. 31, 2020 |
Mar. 31, 2019 |
Dec. 31, 2019 |
| Investment disclosure details |
|
|
|
| Fixed maturities, amortized cost |
$ 65,630
|
|
$ 65,281
|
| Allowance for credit losses |
4
|
|
0
|
| Gross unrealized gains |
2,694
|
|
2,882
|
| Gross unrealized losses |
423
|
|
29
|
| Fixed maturities, at fair value |
67,897
|
|
68,134
|
| Proceeds from sales of fixed maturities classified as available for sale |
388
|
$ 769
|
|
| Gross realized gains |
15
|
21
|
|
| Gross realized losses |
1
|
$ 4
|
|
| U.S. Treasury securities and obligations of U.S. government and government agencies and authorities [Member] |
|
|
|
| Investment disclosure details |
|
|
|
| Fixed maturities, amortized cost |
2,003
|
|
2,076
|
| Allowance for credit losses |
0
|
|
|
| Gross unrealized gains |
53
|
|
19
|
| Gross unrealized losses |
1
|
|
0
|
| Fixed maturities, at fair value |
2,055
|
|
2,095
|
| Obligations of states, municipalities and political subdivisions [Member] |
|
|
|
| Investment disclosure details |
|
|
|
| Fixed maturities, amortized cost |
29,366
|
|
28,356
|
| Allowance for credit losses |
0
|
|
|
| Gross unrealized gains |
1,654
|
|
1,567
|
| Gross unrealized losses |
12
|
|
6
|
| Fixed maturities, at fair value |
31,008
|
|
29,917
|
| Obligations of states, municipalities and political subdivisions, local general obligation [Member] |
|
|
|
| Investment disclosure details |
|
|
|
| Fixed maturities, amortized cost |
15,893
|
|
15,490
|
| Allowance for credit losses |
0
|
|
|
| Gross unrealized gains |
907
|
|
829
|
| Gross unrealized losses |
9
|
|
4
|
| Fixed maturities, at fair value |
16,791
|
|
16,315
|
| Obligations of states, municipalities and political subdivisions, revenue [Member] |
|
|
|
| Investment disclosure details |
|
|
|
| Fixed maturities, amortized cost |
10,158
|
|
9,731
|
| Allowance for credit losses |
0
|
|
|
| Gross unrealized gains |
593
|
|
586
|
| Gross unrealized losses |
3
|
|
2
|
| Fixed maturities, at fair value |
10,748
|
|
10,315
|
| Obligations of states, municipalities and political subdivisions, state general obligation [Member] |
|
|
|
| Investment disclosure details |
|
|
|
| Fixed maturities, amortized cost |
1,149
|
|
1,167
|
| Allowance for credit losses |
0
|
|
|
| Gross unrealized gains |
65
|
|
64
|
| Gross unrealized losses |
0
|
|
0
|
| Fixed maturities, at fair value |
1,214
|
|
1,231
|
| Obligations of states, municipalities and political subdivisions, pre-refunded [Member] |
|
|
|
| Investment disclosure details |
|
|
|
| Fixed maturities, amortized cost |
2,166
|
|
1,968
|
| Allowance for credit losses |
0
|
|
|
| Gross unrealized gains |
89
|
|
88
|
| Gross unrealized losses |
0
|
|
0
|
| Fixed maturities, at fair value |
2,255
|
|
2,056
|
| Debt securities issued by foreign governments [Member] |
|
|
|
| Investment disclosure details |
|
|
|
| Fixed maturities, amortized cost |
1,016
|
|
1,167
|
| Allowance for credit losses |
0
|
|
|
| Gross unrealized gains |
24
|
|
8
|
| Gross unrealized losses |
0
|
|
2
|
| Fixed maturities, at fair value |
1,040
|
|
1,173
|
| Mortgage-backed securities, collateralized mortgage obligations and pass-through securities [Member] |
|
|
|
| Investment disclosure details |
|
|
|
| Fixed maturities, amortized cost |
3,165
|
|
3,192
|
| Allowance for credit losses |
0
|
|
0
|
| Gross unrealized gains |
147
|
|
91
|
| Gross unrealized losses |
5
|
|
3
|
| Fixed maturities, at fair value |
3,307
|
|
3,280
|
| All other corporate bonds [Member] |
|
|
|
| Investment disclosure details |
|
|
|
| Fixed maturities, amortized cost |
30,034
|
|
30,442
|
| Allowance for credit losses |
4
|
|
0
|
| Gross unrealized gains |
816
|
|
1,195
|
| Gross unrealized losses |
405
|
|
18
|
| Fixed maturities, at fair value |
30,441
|
|
31,619
|
| Redeemable preferred stock [Member] |
|
|
|
| Investment disclosure details |
|
|
|
| Fixed maturities, amortized cost |
46
|
|
48
|
| Allowance for credit losses |
0
|
|
|
| Gross unrealized gains |
0
|
|
2
|
| Gross unrealized losses |
0
|
|
0
|
| Fixed maturities, at fair value |
$ 46
|
|
$ 50
|