Acquisition of Ally Financial International Operations - Contractually Required Payments Receivable (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Ally Financial [Member]
Business Acquisition [Line Items]
Finance receivables	$ 15,144
Consumer Finance Receivables [Member] \| Ally Financial [Member]
Business Acquisition [Line Items]
Contractually required payments receivable	10,687
Cash flows not expected to be collected	276
Finance receivables	9,709
Commercial Finance Receivables [Member]
Business Acquisition [Line Items]
Finance receivables		4,834
Commercial Finance Receivables [Member] \| Ally Financial [Member]
Business Acquisition [Line Items]
Contractually required payments receivable	4,947
Cash flows not expected to be collected	27
Finance receivables	$ 4,834

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For receivables acquired in a business combination, excluding certain loans and debt securities acquired in a transfer (as defined), this element represents the best estimate at the acquisition date of the contractual cash flows not expected to be collected, by major class of receivable, such as loans, direct finance leases (as defined), and any other class of receivables.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (b)(3)

-URI http://asc.fasb.org/extlink&oid=39739317&loc=d3e4845-128472

+ Details

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- Definition

For receivables acquired in a business combination, excluding certain loans and debt securities acquired in a transfer (as defined), this element represents the fair value of the receivables acquired, by major class of receivable, such as loans, direct finance leases (as defined), and any other class of receivables.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (b)(1)

-URI http://asc.fasb.org/extlink&oid=39739317&loc=d3e4845-128472

+ Details

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- Definition

For receivables acquired in a business combination, excluding certain loans and debt securities acquired in a transfer (as defined), this element represents the gross contractual amounts receivable, by major class of receivable, such as loans, direct finance leases (as defined), and any other class of receivables.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (b)(2)

-URI http://asc.fasb.org/extlink&oid=39739317&loc=d3e4845-128472

+ Details

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- Details

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- Details

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- Details

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