Long-term Debt - Principal Maturities of Long-Term Debt (Details) - USD ($)	Dec. 31, 2020	Dec. 31, 2019
Principal maturities of long-term debt by type of debt
2021	$ 635,000,000
2022	992,000,000
2023	1,175,000,000
2024	1,300,000,000
2025	1,835,000,000
2026-2067	4,349,000,000
Total principal maturities	18,107,000,000
Long-term debt	17,800,000,000	$ 17,212,000,000
Debt issuance costs	(117,000,000)
Consolidated VIEs
Principal maturities of long-term debt by type of debt
Long-term debt	7,789,000,000	7,643,000,000
Securitizations \| Consolidated VIEs
Principal maturities of long-term debt by type of debt
Amounts drawn	0
Securitizations
Principal maturities of long-term debt by type of debt
Securitizations	7,821,000,000
Senior Debt \| Securitizations
Principal maturities of long-term debt by type of debt
2021	0
2022	0
2023	0
2024	0
2025	0
2026-2067	0
Securitizations	7,821,000,000
Total principal maturities	7,821,000,000
Long-term debt	7,789,000,000
Debt issuance costs	(30,000,000)
Debt issuance costs	$ 33,000,000
Senior Debt \| Securitizations \| Minimum
Long-term debt
Interest rate	0.95%
Senior Debt \| Securitizations \| Maximum
Long-term debt
Interest rate	6.94%
Senior Debt \| Unsecured Notes
Principal maturities of long-term debt by type of debt
2021	$ 635,000,000
2022	992,000,000
2023	1,175,000,000
2024	1,300,000,000
2025	1,835,000,000
2026-2067	3,999,000,000
Total principal maturities	9,936,000,000
Long-term debt	9,839,000,000
Debt issuance costs	$ (87,000,000)
Senior Debt \| Unsecured Notes \| Minimum
Long-term debt
Interest rate	4.00%
Senior Debt \| Unsecured Notes \| Maximum
Long-term debt
Interest rate	8.88%
Junior Subordinated Debt
Principal maturities of long-term debt by type of debt
2021	$ 0
2022	0
2023	0
2024	0
2025	0
2026-2067	350,000,000
Total principal maturities	350,000,000
Long-term debt	172,000,000
Debt issuance costs	0
OMFC
Principal maturities of long-term debt by type of debt
Long-term debt	17,800,000,000	17,212,000,000
OMFC \| Consolidated VIEs
Principal maturities of long-term debt by type of debt
Long-term debt	$ 7,800,000,000	$ 7,600,000,000
OMFC \| Junior Subordinated Debt
Long-term debt
Effective interest rate	1.99%

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Debt Issuance Costs, Excluded From Direct Deduction From Long Term Debt

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Represents the amount of long-term debt with variable monthly repayments of the principal.

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Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

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Effective interest rate for the funds borrowed under the debt agreement considering interest compounding and original issue discount or premium.

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Contractual interest rate for funds borrowed, under the debt agreement.

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Amount, after accumulated amortization, of debt issuance costs. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.

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Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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Amount of long-term debt payable, sinking fund requirement, and other securities issued that are redeemable by holder at fixed or determinable price and date, maturing after fifth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Amount of long-term debt payable, sinking fund requirement, and other securities issued that are redeemable by holder at fixed or determinable price and date, maturing in next fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Amount of long-term debt payable, sinking fund requirement, and other securities issued that are redeemable by holder at fixed or determinable price and date, maturing in fourth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Amount of long-term debt payable, sinking fund requirement, and other securities issued that are redeemable by holder at fixed or determinable price and date, maturing in third fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Amount of long-term debt payable, sinking fund requirement, and other securities issued that are redeemable by holder at fixed or determinable price and date, maturing in second fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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