Description of Business, Basis of Presentation, and Changes in Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2012

Organization, Consolidation and Presentation of Financial Statements [Abstract]

ResCap Results of Operations [Table Text Block]

As of December 31, 2012, due to Ally Bank performing certain mortgage activities during the bankruptcy process and the related uncertainty associated with the timing of resolution of the ResCap bankruptcy, we did not classify ResCap as a discontinued operation. Accordingly, ResCap's results are presented as continuing operations within our Consolidated Statement of Income for periods prior to May 14, 2012. Our Consolidated Statement of Income includes the following for ResCap's results of operations (amounts presented are before the elimination of balances and transactions with Ally).

Year ended December 31, ($ in millions)	2012		2011			2010
Total net revenue	$	476	$	632		$	2,051
Provision for loan losses	—		24			(7		)
Total noninterest expense	437		1,438			1,526
Income (loss) from continuing operations before income tax expense	39		(830		)	532
Income tax expense from continuing operations	7		15			7
Net income (loss) from continuing operations	$	32	$	(845	)	$	525