Investments (Mortgage Loans by Portfolio Segment) (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Accounts, Notes, Loans and Financing Receivable [Line Items]
Mortgage Loans, Gross	$ 66,378	$ 65,591
Allowance for Credit Loss	(452)	(289)
Subtotal mortgage loans, net	65,926	65,302
Mortgage Loans on Real Estate, Commercial and Consumer, Net	66,102	65,549
Total mortgage loans held-for-investment, net	66,102	65,490
Mortgage loans held-for-sale	$ 0	$ 59
Percentage Of mortgage total recorded investment To Mortgage Loans On Real Estate Commercial and Consumer Net	100.40%	100.00%
Percentage of Allowance for Credit Losses to Mortgage Loans On Real Estate Commercial And Consumer Net	(0.70%)	(0.40%)
Percentage Of Mortgage Loans Held For Investment Net To Mortgage Loans On Real Estate Commercial And Consumer Net	99.70%	99.60%
Percentage Of Loans And Leases Receivable Consumer Other To Mortgage Loans On Real Estate Commercial And Consumer Net	0.30%	0.30%
Percentage of total mortgage loans held-for-investments	100.00%	99.90%
Percentage of mortgage loans held-for-sale	0.00%	0.10%
Percentage Of Mortgage Loans On Real Estate To Mortgage Loans On Real Estate Commercial And Consumer Net	100.00%	100.00%
Residential mortgage loans - FVO
Accounts, Notes, Loans and Financing Receivable [Line Items]
Mortgage Loans on Real Estate, Commercial and Consumer, Net	$ 176	$ 188
Agricultural Mortgage Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Mortgage Loans, Gross	$ 15,873	$ 15,705
Percentage Of Mortgage Loans, Gross	24.00%	23.90%
Commercial Mortgage Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Mortgage Loans, Gross	$ 38,124	$ 37,311
Percentage Of Mortgage Loans, Gross	57.70%	56.90%
Residential Mortgage Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Mortgage Loans, Gross	$ 12,381	$ 12,575
Percentage Of Mortgage Loans, Gross	18.70%	19.20%

Percentage Of Financing Receivable, Gross

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Percentage of loans and leases receivable consumer other to total mortgage loans on real estate.

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Percentage of Mortgage Loans Held-for-investment, net to total Mortgage Loans on Real Estate.

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Percentage of Mortgage Loans Held For Investment to total Mortgage Loans on Real Estate.

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Percentage of Mortgage Loans On Real Estate to total Mortgage Loans on Real Estate.

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Percentage Of Allowance for Credit Losses for Financing Receivables

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Percentage of mortgage loans held-for-sale

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Percentage of total mortgage loans held-for-investments

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Amount of allowance for credit loss on financing receivable. Excludes allowance for financing receivable covered under loss sharing agreement.

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Amount after allowance and deduction of deferred interest and fees, unamortized costs and premiums and discounts from face amounts, of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Excludes loans and leases covered under loss sharing agreements and loans held for sale.

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Amount, before valuation allowance, of financing receivable classified as held-for-sale.

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The balance represents the amount of loans that are secured by real estate mortgages, offset by the reserve to cover probable credit losses on the loan portfolio.

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Amount, before allowance for credit loss, of financing receivable.

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Amount, after allowance for credit loss, of financing receivable. Excludes financing receivable covered under loss sharing agreement.

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