Regulatory Capital (Tables)

3 Months Ended

Mar. 31, 2013

Regulatory Capital Requirements [Abstract]

Schedule of Compliance with Regulatory Capital Requirements under Banking Regulations [Table Text Block]

The following table summarizes our capital ratios.

	March 31, 2013				December 31, 2012				Required minimum			Well-capitalized minimum
($ in millions)	Amount		Ratio		Amount		Ratio
Risk-based capital
Tier 1 (to risk-weighted assets)
Ally Financial Inc.	$	20,663	14.59	%	$	20,232	13.13	%	4.00	%		6.00%
Ally Bank	14,380		16.68		14,136		16.26		4.00			6.00
Total (to risk-weighted assets)
Ally Financial Inc.	$	22,084	15.59	%	$	21,669	14.07	%	8.00	%		10.00%
Ally Bank	15,073		17.48		14,827		17.06		8.00			10.00
Tier 1 leverage (to adjusted quarterly average assets) (a)
Ally Financial Inc.	$	20,663	12.01	%	$	20,232	11.16	%	3.00–4.00%			(b)
Ally Bank	14,380		15.59		14,136		15.30		15.00		(c)	5.00%
Tier 1 common (to risk-weighted assets)
Ally Financial Inc.	$	11,180	7.89	%	$	10,749	6.98	%	n/a			n/a
Ally Bank	n/a		n/a		n/a		n/a		n/a			n/a

n/a = not applicable

(a) Federal regulatory reporting guidelines require the calculation of adjusted quarterly average assets using a daily average methodology.

(b) There is no Tier 1 leverage component in the definition of a well-capitalized bank holding company.

(c) Ally Bank, in accordance with the CLMA, is required to maintain a Tier 1 leverage ratio of at least 15%.