Securitizations And Variable Interest Entities (Schedule Of Cash Flow Received and Paid To Nonconsolidated Securitization Entities) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
Mar. 31, 2013	Mar. 31, 2012
Consumer Loans Auto Financing Receivable [Member]
Cash Flow Received and Paid to Nonconsolidated Securitization Entities [Line Items]
Cash Flows Between Transferor and Transferee, Proceeds from New Transfers	$ 0	$ 0
Cash flows received on retained interests in securitization entities		0
Cash Flows Between Transferor and Transferee, Servicing Fees	4	0
Purchases of previously transferred financial assets		0
Representations and warranties obligations	0	0
Cash Flows Between Transferor and Transferee, Receipts on Transferor's Interest in Transferred Financial Assets, Other	0	0
US Government-sponsored Enterprises [Member]
Cash Flow Received and Paid to Nonconsolidated Securitization Entities [Line Items]
Securitization or Asset-backed Financing Arrangement, Financial Asset for which Transfer is Accounted as Sale, Gain (Loss) on Sale	93	28
Cash Flows Between Transferor and Transferee, Proceeds from New Transfers	7,580	10,645
Cash flows received on retained interests in securitization entities		0
Cash Flows Between Transferor and Transferee, Servicing Fees	119	249
Purchases of previously transferred financial assets		(580)
Representations and warranties obligations	(23)	(19)
Cash Flows Between Transferor and Transferee, Receipts on Transferor's Interest in Transferred Financial Assets, Other	3	10
Private Placement [Member]
Cash Flow Received and Paid to Nonconsolidated Securitization Entities [Line Items]
Cash Flows Between Transferor and Transferee, Proceeds from New Transfers	0	0
Cash flows received on retained interests in securitization entities		14
Cash Flows Between Transferor and Transferee, Servicing Fees	0	48
Purchases of previously transferred financial assets		(8)
Representations and warranties obligations	0	(4)
Cash Flows Between Transferor and Transferee, Receipts on Transferor's Interest in Transferred Financial Assets, Other	$ 0	$ 23

Cash Flows between a transferor and a transferee attributable to newly transferred assets related to either a securitization, asset-backed financing arrangement, or similar transfer in which the transferor has continuing involvement with the transferred financial assets underlying the transaction (including, but not limited to, servicing, recourse, and restrictions on transferor's interests in the transferred financial assets).

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Cash Flows between a transferor and a transferee attributable to purchases of previously transferred financial assets (or its underlying collateral) related to a securitization, asset-backed financing arrangement, or similar transfer in which the transferor has continuing involvement with the transferred financial assets underlying the transaction (including, but not limited to, servicing, recourse, and restrictions on transferor's interests in the transferred financial assets).

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- Definition

Cash flows between transferor and a transferee attributable to the transferor's interests related to a securitization, asset-backed financing arrangement, or similar transfer in which the transferor will have continuing involvement with the transferred financial assets underlying the transaction (including, but not limited to, servicing, recourse, and restrictions on transferor's interests in the transferred financial assets).

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- Definition

Cash Flows between a transferee and a transferor attributable to servicing fees related to a securitization, asset-backed financing arrangement, or similar transfer in which the transferor has continuing involvement with the transferred financial assets underlying the transaction (including, but not limited to, servicing, recourse, and restrictions on transferor's interests in the transferred financial assets).

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- Definition

Reflects, by transferred financial asset type, the amount of sales proceeds in excess of or deficient from the sum of the carrying amounts of transferred financial assets plus transaction costs, including those transactions in which the seller/transferor has continuing involvement with the financial assets that have been transferred.

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