Consolidated Summary of Investments - Other Than Investments in Related Parties (Details) $ in Millions	Dec. 31, 2019 USD ($)
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items]
Cost or Amortized Cost	$ 441,580
Estimated Fair Value	473,795
Fixed Maturities [Member]
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items]
Cost or Amortized Cost	297,655
Estimated Fair Value	327,820
Amount at Which Shown on Balance Sheet	327,820
Foreign government
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items]
Cost or Amortized Cost	58,840
Estimated Fair Value	67,229
Amount at Which Shown on Balance Sheet	67,229
U.S. government and agency
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items]
Cost or Amortized Cost	37,586
Estimated Fair Value	42,084
Amount at Which Shown on Balance Sheet	42,084
Public utilities
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items]
Cost or Amortized Cost	12,067
Estimated Fair Value	13,807
Amount at Which Shown on Balance Sheet	13,807
Municipals
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items]
Cost or Amortized Cost	11,081
Estimated Fair Value	13,053
Amount at Which Shown on Balance Sheet	13,053
All other corporate bonds
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items]
Cost or Amortized Cost	125,296
Estimated Fair Value	136,914
Amount at Which Shown on Balance Sheet	136,914
Total bonds
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items]
Cost or Amortized Cost	244,870
Estimated Fair Value	273,087
Amount at Which Shown on Balance Sheet	273,087
Mortgage-backed and asset-backed securities
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items]
Cost or Amortized Cost	51,691
Estimated Fair Value	53,536
Amount at Which Shown on Balance Sheet	53,536
Redeemable preferred stock
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items]
Cost or Amortized Cost	1,094
Estimated Fair Value	1,197
Amount at Which Shown on Balance Sheet	1,197
Unit-linked and FVO Securities
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items]
Cost or Amortized Cost	11,329
Estimated Fair Value	13,102
Amount at Which Shown on Balance Sheet	13,102
Equity Securities, Investment Summary [Member]
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items]
Cost or Amortized Cost	1,065
Estimated Fair Value	1,342
Amount at Which Shown on Balance Sheet	1,342
Industrial, miscellaneous and all other
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items]
Cost or Amortized Cost	508
Estimated Fair Value	700
Amount at Which Shown on Balance Sheet	700
Public utilities
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items]
Cost or Amortized Cost	67
Estimated Fair Value	66
Amount at Which Shown on Balance Sheet	66
Banks, trust and insurance companies
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items]
Cost or Amortized Cost	105
Estimated Fair Value	178
Amount at Which Shown on Balance Sheet	178
Non-redeemable Preferred Stock
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items]
Cost or Amortized Cost	385
Estimated Fair Value	398
Amount at Which Shown on Balance Sheet	398
Held-for-investment
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items]
Cost or Amortized Cost	80,529
Estimated Fair Value	80,529
Policy loans
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items]
Cost or Amortized Cost	9,680
Estimated Fair Value	9,680
Real estate and real estate joint ventures
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items]
Cost or Amortized Cost	10,705
Estimated Fair Value	10,705
Real estate acquired in satisfaction of debt
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items]
Cost or Amortized Cost	36
Estimated Fair Value	36
Other limited partnership interests
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items]
Cost or Amortized Cost	7,716
Estimated Fair Value	7,716
Short-term investments
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items]
Cost or Amortized Cost	3,850
Estimated Fair Value	3,850
Other invested assets
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items]
Cost or Amortized Cost	19,015
Estimated Fair Value	$ 19,015