Investments - Mortgage Loans, Net by Property Type and Geographic Region (Details) - USD ($) $ in Millions	Jun. 30, 2021	Dec. 31, 2020	Jun. 30, 2022	Dec. 31, 2021
Loans and Leases Receivable Disclosure [Line Items]
Mortgage loans, net of allowances				$ 24,148
Commercial mortgage loans
Loans and Leases Receivable Disclosure [Line Items]
Mortgage loans, net of allowances			$ 19,339	16,897
Commercial mortgage loans | Property Type Concentration Risk | Mortgage Loans, Net
Loans and Leases Receivable Disclosure [Line Items]
Percentage concentration risk	100.00%	100.00%
Commercial mortgage loans | Geographic Concentration Risk | Mortgage Loans, Net
Loans and Leases Receivable Disclosure [Line Items]
Percentage concentration risk	100.00%	100.00%
Commercial mortgage loans | Total U.S. Region
Loans and Leases Receivable Disclosure [Line Items]
Mortgage loans, net of allowances			16,698	14,796
Commercial mortgage loans | Total U.S. Region | Geographic Concentration Risk | Mortgage Loans, Net
Loans and Leases Receivable Disclosure [Line Items]
Percentage concentration risk	86.30%	87.50%
Commercial mortgage loans | East North Central
Loans and Leases Receivable Disclosure [Line Items]
Mortgage loans, net of allowances			1,658	1,697
Commercial mortgage loans | East North Central | Geographic Concentration Risk | Mortgage Loans, Net
Loans and Leases Receivable Disclosure [Line Items]
Percentage concentration risk	8.60%	10.00%
Commercial mortgage loans | East South Central
Loans and Leases Receivable Disclosure [Line Items]
Mortgage loans, net of allowances			447	470
Commercial mortgage loans | East South Central | Geographic Concentration Risk | Mortgage Loans, Net
Loans and Leases Receivable Disclosure [Line Items]
Percentage concentration risk	2.30%	2.80%
Commercial mortgage loans | Middle Atlantic
Loans and Leases Receivable Disclosure [Line Items]
Mortgage loans, net of allowances			4,118	3,637
Commercial mortgage loans | Middle Atlantic | Geographic Concentration Risk | Mortgage Loans, Net
Loans and Leases Receivable Disclosure [Line Items]
Percentage concentration risk	21.30%	21.50%
Commercial mortgage loans | Mountain
Loans and Leases Receivable Disclosure [Line Items]
Mortgage loans, net of allowances			935	460
Commercial mortgage loans | Mountain | Geographic Concentration Risk | Mortgage Loans, Net
Loans and Leases Receivable Disclosure [Line Items]
Percentage concentration risk	4.80%	2.70%
Commercial mortgage loans | New England
Loans and Leases Receivable Disclosure [Line Items]
Mortgage loans, net of allowances			1,118	453
Commercial mortgage loans | New England | Geographic Concentration Risk | Mortgage Loans, Net
Loans and Leases Receivable Disclosure [Line Items]
Percentage concentration risk	5.80%	2.70%
Commercial mortgage loans | Pacific
Loans and Leases Receivable Disclosure [Line Items]
Mortgage loans, net of allowances			4,060	3,994
Commercial mortgage loans | Pacific | Geographic Concentration Risk | Mortgage Loans, Net
Loans and Leases Receivable Disclosure [Line Items]
Percentage concentration risk	21.00%	23.60%
Commercial mortgage loans | South Atlantic
Loans and Leases Receivable Disclosure [Line Items]
Mortgage loans, net of allowances			2,886	2,817
Commercial mortgage loans | South Atlantic | Geographic Concentration Risk | Mortgage Loans, Net
Loans and Leases Receivable Disclosure [Line Items]
Percentage concentration risk	14.90%	16.70%
Commercial mortgage loans | West North Central
Loans and Leases Receivable Disclosure [Line Items]
Mortgage loans, net of allowances			273	271
Commercial mortgage loans | West North Central | Geographic Concentration Risk | Mortgage Loans, Net
Loans and Leases Receivable Disclosure [Line Items]
Percentage concentration risk	1.40%	1.60%
Commercial mortgage loans | West South Central
Loans and Leases Receivable Disclosure [Line Items]
Mortgage loans, net of allowances			1,203	997
Commercial mortgage loans | West South Central | Geographic Concentration Risk | Mortgage Loans, Net
Loans and Leases Receivable Disclosure [Line Items]
Percentage concentration risk	6.20%	5.90%
Commercial mortgage loans | UNITED KINGDOM
Loans and Leases Receivable Disclosure [Line Items]
Mortgage loans, net of allowances			1,703	1,279
Commercial mortgage loans | UNITED KINGDOM | Geographic Concentration Risk | Mortgage Loans, Net
Loans and Leases Receivable Disclosure [Line Items]
Percentage concentration risk	8.80%	7.60%
Commercial mortgage loans | Other
Loans and Leases Receivable Disclosure [Line Items]
Mortgage loans, net of allowances			938	822
Commercial mortgage loans | Other | Geographic Concentration Risk | Mortgage Loans, Net
Loans and Leases Receivable Disclosure [Line Items]
Percentage concentration risk	4.90%	4.90%
Commercial mortgage loans | International
Loans and Leases Receivable Disclosure [Line Items]
Mortgage loans, net of allowances			2,641	2,101
Commercial mortgage loans | International | Geographic Concentration Risk | Mortgage Loans, Net
Loans and Leases Receivable Disclosure [Line Items]
Percentage concentration risk	13.70%	12.50%
Commercial mortgage loans | Hotels
Loans and Leases Receivable Disclosure [Line Items]
Mortgage loans, net of allowances			1,730	1,727
Commercial mortgage loans | Hotels | Property Type Concentration Risk | Mortgage Loans, Net
Loans and Leases Receivable Disclosure [Line Items]
Percentage concentration risk	8.90%	10.20%
Commercial mortgage loans | Retail
Loans and Leases Receivable Disclosure [Line Items]
Mortgage loans, net of allowances			1,929	2,022
Commercial mortgage loans | Retail | Property Type Concentration Risk | Mortgage Loans, Net
Loans and Leases Receivable Disclosure [Line Items]
Percentage concentration risk	10.00%	12.00%
Commercial mortgage loans | Office building
Loans and Leases Receivable Disclosure [Line Items]
Mortgage loans, net of allowances			5,148	4,870
Commercial mortgage loans | Office building | Property Type Concentration Risk | Mortgage Loans, Net
Loans and Leases Receivable Disclosure [Line Items]
Percentage concentration risk	26.60%	28.80%
Commercial mortgage loans | Industrial
Loans and Leases Receivable Disclosure [Line Items]
Mortgage loans, net of allowances			2,459	2,336
Commercial mortgage loans | Industrial | Property Type Concentration Risk | Mortgage Loans, Net
Loans and Leases Receivable Disclosure [Line Items]
Percentage concentration risk	12.70%	13.80%
Commercial mortgage loans | Apartment
Loans and Leases Receivable Disclosure [Line Items]
Mortgage loans, net of allowances			6,068	4,626
Commercial mortgage loans | Apartment | Property Type Concentration Risk | Mortgage Loans, Net
Loans and Leases Receivable Disclosure [Line Items]
Percentage concentration risk	31.40%	27.40%
Commercial mortgage loans | Other commercial
Loans and Leases Receivable Disclosure [Line Items]
Mortgage loans, net of allowances			$ 2,005	$ 1,316
Commercial mortgage loans | Other commercial | Property Type Concentration Risk | Mortgage Loans, Net
Loans and Leases Receivable Disclosure [Line Items]
Percentage concentration risk	10.40%	7.80%