Regulatory Capital (Tables)

12 Months Ended

Dec. 31, 2015

Regulatory Capital Requirements [Abstract]

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

The following table summarizes our capital ratios under the U.S. Basel III capital framework.

	Under Basel III				Under Basel I
	December 31, 2015 (a)				December 31, 2014 (b)				Required minimum			Well-capitalized minimum
($ in millions)	Amount		Ratio		Amount		Ratio
Risk-based capital
Common Equity Tier 1 (to risk-weighted assets) (c)
Ally Financial Inc.	$	12,507	9.21	%	$	12,588	9.64	%	4.50	%		(d)
Ally Bank	16,594		17.05		16,022		16.89		4.50			6.50	%
Tier 1 (to risk-weighted assets)
Ally Financial Inc.	$	15,077	11.10	%	$	16,389	12.55	%	6.00	%		6.00	%
Ally Bank	16,594		17.05		16,022		16.89		6.00			8.00
Total (to risk-weighted assets)
Ally Financial Inc.	$	17,005	12.52	%	$	17,294	13.24	%	8.00	%		10.00	%
Ally Bank	17,043		17.51		16,468		17.36		8.00			10.00
Tier 1 leverage (to adjusted quarterly average assets) (e)
Ally Financial Inc.	$	15,077	9.73	%	$	16,389	10.94	%	4.00	%		(d)
Ally Bank	16,594		15.38		16,022		15.44		15.00		(f)	5.00	%

(a) U.S. Basel III became effective for us on January 1, 2015, subject to transitional provisions primarily related to deductions and adjustments impacting Common Equity Tier 1 capital and Tier 1 capital.

(b) Capital ratios as of December 31, 2014, are presented under the U.S. Basel I capital framework.

(c) Previously referred to as Tier 1 Common Equity under the U.S. Basel I capital framework.

(d) Currently, there is no ratio component for determining whether a BHC is "well-capitalized."

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

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