Finance Receivables and Loans, Net (Schedule of Accounts, Notes, Loans and Financing Receivables) (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Accounts, Notes, Loans and Financing Receivable [Line Items]
Finance receivables and loans, net	$ 129,926	$ 122,893
Loans and finance receivables
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unamortized premiums and discounts and deferred fees and costs	587	551
Consumer portfolio segment \| Consumer loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Finance receivables and loans, net	87,240	81,821
Consumer portfolio segment \| Automobile loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Finance receivables and loans, net	70,539	68,071
Consumer portfolio segment \| Residential mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Finance receivables and loans, net	16,701	13,750
Consumer portfolio segment \| Mortgage Finance
Accounts, Notes, Loans and Financing Receivable [Line Items]
Finance receivables and loans, net	15,155	11,657
Interest-only mortgage loans	$ 18	20
Consumer portfolio segment \| Mortgage Finance \| 2019, or sooner
Accounts, Notes, Loans and Financing Receivable [Line Items]
Interest-only mortgage loan portfolio principal amortization	34.00%
Consumer portfolio segment \| Mortgage Finance \| 2020, or sooner
Accounts, Notes, Loans and Financing Receivable [Line Items]
Interest-only mortgage loan portfolio principal amortization	41.00%
Consumer portfolio segment \| Mortgage - Legacy
Accounts, Notes, Loans and Financing Receivable [Line Items]
Finance receivables and loans, net	$ 1,546	2,093
Interest-only mortgage loans	$ 341	496
Interest-only mortgage loans having exited the interest-only period	99.00%
Commercial portfolio segment \| Commercial loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Finance receivables and loans, net	$ 42,686	41,072
Commercial portfolio segment \| Commercial and industrial automotive
Accounts, Notes, Loans and Financing Receivable [Line Items]
Finance receivables and loans, net	33,672	33,025
Commercial portfolio segment \| Commercial and industrial other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Finance receivables and loans, net	4,205	3,887
Commercial portfolio segment \| Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Finance receivables and loans, net	$ 4,809	$ 4,160

Held For Investment Mortgage Finance Receivables Exited Interest Only Mortgage Loans

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Held for investment mortgage finance receivables interest only mortgage loans.

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Interest-only mortgage loan portfolio principal amortization

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Amount before allowance of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes loans and leases covered under loss sharing agreements.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 45
-Paragraph 2
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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 20
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6378536&loc=d3e10092-111533

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