Investments - Investments - Mortgage Loans by Region and Property Type (Details) - USD ($) $ in Millions	Jun. 30, 2026	Mar. 31, 2026	Dec. 31, 2025	Jun. 30, 2025	Mar. 31, 2025	Dec. 31, 2024
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, after Allowance for Credit Loss	$ 7,262		$ 6,837
Commercial Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	$ 7,311		$ 6,886
Percent of Total	100.00%		100.00%
Financing Receivable, Allowance for Credit Loss	$ (49)	$ (49)	$ (49)	$ (43)	$ (43)	$ (44)
Financing Receivable, after Allowance for Credit Loss	7,262		6,837
Commercial Loan [Member] \| Industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	$ 3,660		$ 3,208
Percent of Total	50.10%		46.60%
Commercial Loan [Member] \| Multifamily
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	$ 2,207		$ 2,209
Percent of Total	30.20%		32.10%
Commercial Loan [Member] \| Office
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	$ 373		$ 399
Percent of Total	5.10%		5.80%
Commercial Loan [Member] \| Retail
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	$ 991		$ 992
Percent of Total	13.50%		14.40%
Commercial Loan [Member] \| Residential Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	$ 80		$ 78
Percent of Total	1.10%		1.10%
Commercial Loan [Member] \| Regional Shopping Malls
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	$ 0		$ 0
East North Central [Member] \| Commercial Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	$ 459		$ 401
Percent of Total	6.30%		5.80%
Middle Atlantic [Member] \| Commercial Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	$ 275		$ 275
Percent of Total	3.80%		4.00%
Mountain [Member] \| Commercial Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	$ 892		$ 903
Percent of Total	12.20%		13.10%
New England [Member] \| Commercial Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	$ 328		$ 351
Percent of Total	4.50%		5.10%
Pacific [Member] \| Commercial Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	$ 1,424		$ 1,417
Percent of Total	19.40%		20.60%
South Atlantic [Member] \| Commercial Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	$ 2,158		$ 2,005
Percent of Total	29.50%		29.10%
West North Central [Member] \| Commercial Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	$ 129		$ 128
Percent of Total	1.80%		1.90%
West South Central [Member] \| Commercial Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	$ 759		$ 720
Percent of Total	10.40%		10.40%
Region Others [Member] \| Commercial Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	$ 887		$ 686
Percent of Total	12.10%		10.00%