Investments - Mortgage Loans, Net by Property Type and Geographic Region (Details) - Commercial mortgage loans - USD ($) $ in Millions	Mar. 31, 2023	Dec. 31, 2022
Loans and Leases Receivable Disclosure [Line Items]
Mortgage loans, net of allowances	$ 21,023	$ 20,108
Property Type Concentration Risk | Mortgage Loans, Net
Loans and Leases Receivable Disclosure [Line Items]
Percentage concentration risk	100.00%	100.00%
Geographic Concentration Risk | Mortgage Loans, Net
Loans and Leases Receivable Disclosure [Line Items]
Percentage concentration risk	100.00%	100.00%
Total U.S. Region
Loans and Leases Receivable Disclosure [Line Items]
Mortgage loans, net of allowances	$ 17,615	$ 16,860
Total U.S. Region | Geographic Concentration Risk | Mortgage Loans, Net
Loans and Leases Receivable Disclosure [Line Items]
Percentage concentration risk	83.80%	83.90%
East North Central
Loans and Leases Receivable Disclosure [Line Items]
Mortgage loans, net of allowances	$ 1,438	$ 1,437
East North Central | Geographic Concentration Risk | Mortgage Loans, Net
Loans and Leases Receivable Disclosure [Line Items]
Percentage concentration risk	6.80%	7.10%
East South Central
Loans and Leases Receivable Disclosure [Line Items]
Mortgage loans, net of allowances	$ 422	$ 413
East South Central | Geographic Concentration Risk | Mortgage Loans, Net
Loans and Leases Receivable Disclosure [Line Items]
Percentage concentration risk	2.00%	2.10%
Middle Atlantic
Loans and Leases Receivable Disclosure [Line Items]
Mortgage loans, net of allowances	$ 5,561	$ 5,183
Middle Atlantic | Geographic Concentration Risk | Mortgage Loans, Net
Loans and Leases Receivable Disclosure [Line Items]
Percentage concentration risk	26.50%	25.80%
Mountain
Loans and Leases Receivable Disclosure [Line Items]
Mortgage loans, net of allowances	$ 923	$ 898
Mountain | Geographic Concentration Risk | Mortgage Loans, Net
Loans and Leases Receivable Disclosure [Line Items]
Percentage concentration risk	4.40%	4.50%
New England
Loans and Leases Receivable Disclosure [Line Items]
Mortgage loans, net of allowances	$ 1,071	$ 1,076
New England | Geographic Concentration Risk | Mortgage Loans, Net
Loans and Leases Receivable Disclosure [Line Items]
Percentage concentration risk	5.10%	5.40%
Pacific
Loans and Leases Receivable Disclosure [Line Items]
Mortgage loans, net of allowances	$ 4,033	$ 3,781
Pacific | Geographic Concentration Risk | Mortgage Loans, Net
Loans and Leases Receivable Disclosure [Line Items]
Percentage concentration risk	19.20%	18.80%
South Atlantic
Loans and Leases Receivable Disclosure [Line Items]
Mortgage loans, net of allowances	$ 2,876	$ 2,756
South Atlantic | Geographic Concentration Risk | Mortgage Loans, Net
Loans and Leases Receivable Disclosure [Line Items]
Percentage concentration risk	13.60%	13.70%
West North Central
Loans and Leases Receivable Disclosure [Line Items]
Mortgage loans, net of allowances	$ 225	$ 231
West North Central | Geographic Concentration Risk | Mortgage Loans, Net
Loans and Leases Receivable Disclosure [Line Items]
Percentage concentration risk	1.10%	1.10%
West South Central
Loans and Leases Receivable Disclosure [Line Items]
Mortgage loans, net of allowances	$ 1,066	$ 1,085
West South Central | Geographic Concentration Risk | Mortgage Loans, Net
Loans and Leases Receivable Disclosure [Line Items]
Percentage concentration risk	5.10%	5.40%
UNITED KINGDOM
Loans and Leases Receivable Disclosure [Line Items]
Mortgage loans, net of allowances	$ 1,970	$ 1,898
UNITED KINGDOM | Geographic Concentration Risk | Mortgage Loans, Net
Loans and Leases Receivable Disclosure [Line Items]
Percentage concentration risk	9.40%	9.40%
Other
Loans and Leases Receivable Disclosure [Line Items]
Mortgage loans, net of allowances	$ 1,438	$ 1,350
Other | Geographic Concentration Risk | Mortgage Loans, Net
Loans and Leases Receivable Disclosure [Line Items]
Percentage concentration risk	6.80%	6.70%
International
Loans and Leases Receivable Disclosure [Line Items]
Mortgage loans, net of allowances	$ 3,408	$ 3,248
International | Geographic Concentration Risk | Mortgage Loans, Net
Loans and Leases Receivable Disclosure [Line Items]
Percentage concentration risk	16.20%	16.10%
Hotels
Loans and Leases Receivable Disclosure [Line Items]
Mortgage loans, net of allowances	$ 1,873	$ 1,855
Hotels | Property Type Concentration Risk | Mortgage Loans, Net
Loans and Leases Receivable Disclosure [Line Items]
Percentage concentration risk	8.90%	9.20%
Retail
Loans and Leases Receivable Disclosure [Line Items]
Mortgage loans, net of allowances	$ 1,450	$ 1,454
Retail | Property Type Concentration Risk | Mortgage Loans, Net
Loans and Leases Receivable Disclosure [Line Items]
Percentage concentration risk	6.90%	7.20%
Office building
Loans and Leases Receivable Disclosure [Line Items]
Mortgage loans, net of allowances	$ 4,535	$ 4,651
Office building | Property Type Concentration Risk | Mortgage Loans, Net
Loans and Leases Receivable Disclosure [Line Items]
Percentage concentration risk	21.60%	23.10%
Industrial
Loans and Leases Receivable Disclosure [Line Items]
Mortgage loans, net of allowances	$ 2,242	$ 2,047
Industrial | Property Type Concentration Risk | Mortgage Loans, Net
Loans and Leases Receivable Disclosure [Line Items]
Percentage concentration risk	10.70%	10.20%
Apartment
Loans and Leases Receivable Disclosure [Line Items]
Mortgage loans, net of allowances	$ 7,506	$ 6,692
Apartment | Property Type Concentration Risk | Mortgage Loans, Net
Loans and Leases Receivable Disclosure [Line Items]
Percentage concentration risk	35.70%	33.30%
Other commercial
Loans and Leases Receivable Disclosure [Line Items]
Mortgage loans, net of allowances	$ 3,417	$ 3,409
Other commercial | Property Type Concentration Risk | Mortgage Loans, Net
Loans and Leases Receivable Disclosure [Line Items]
Percentage concentration risk	16.20%	17.00%