Consolidated Summary of Investments - Other Than Investments in Related Parties (Details) $ in Millions	Dec. 31, 2020 USD ($)
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items]
Cost or Amortized Cost	$ 462,993
Estimated Fair Value	508,519
Fixed Maturities [Member]
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items]
Cost or Amortized Cost	310,811
Estimated Fair Value	354,809
Amount at Which Shown on Balance Sheet	354,809
Foreign government
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items]
Cost or Amortized Cost	63,243
Estimated Fair Value	71,699
Amount at Which Shown on Balance Sheet	71,699
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	39,094
Estimated Fair Value	47,100
Amount at Which Shown on Balance Sheet	47,100
Public utilities
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items]
Cost or Amortized Cost	12,399
Estimated Fair Value	14,948
Amount at Which Shown on Balance Sheet	14,948
Municipals
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items]
Cost or Amortized Cost	10,982
Estimated Fair Value	13,722
Amount at Which Shown on Balance Sheet	13,722
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	127,375
Estimated Fair Value	146,741
Amount at Which Shown on Balance Sheet	146,741
Total bonds
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items]
Cost or Amortized Cost	253,093
Estimated Fair Value	294,210
Amount at Which Shown on Balance Sheet	294,210
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	56,709
Estimated Fair Value	59,464
Amount at Which Shown on Balance Sheet	59,464
Redeemable preferred stock
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items]
Cost or Amortized Cost	1,009
Estimated Fair Value	1,135
Amount at Which Shown on Balance Sheet	1,135
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	11,339
Estimated Fair Value	13,319
Amount at Which Shown on Balance Sheet	13,319
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	941
Estimated Fair Value	1,079
Amount at Which Shown on Balance Sheet	1,079
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	493
Estimated Fair Value	596
Amount at Which Shown on Balance Sheet	596
Public utilities
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items]
Cost or Amortized Cost	88
Estimated Fair Value	52
Amount at Which Shown on Balance Sheet	52
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	63
Estimated Fair Value	131
Amount at Which Shown on Balance Sheet	131
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	297
Estimated Fair Value	300
Amount at Which Shown on Balance Sheet	300
Held-for-investment
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items]
Cost or Amortized Cost	84,509
Estimated Fair Value	83,919
Policy loans
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items]
Cost or Amortized Cost	9,493
Estimated Fair Value	9,493
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	11,913
Estimated Fair Value	11,913
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	20
Estimated Fair Value	20
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	9,470
Estimated Fair Value	9,470
Short-term investments
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items]
Cost or Amortized Cost	3,904
Estimated Fair Value	3,904
Other invested assets
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items]
Cost or Amortized Cost	20,593
Estimated Fair Value	$ 20,593