Regulatory Capital and Other Regulatory Matters (Tables)

6 Months Ended

Jun. 30, 2017

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.

	June 30, 2017				December 31, 2016				Required minimum			Well-capitalized minimum
($ in millions)	Amount		Ratio		Amount		Ratio
Capital ratios
Common Equity Tier 1 (to risk-weighted assets)
Ally Financial Inc.	$	13,066	9.47	%	$	12,978	9.37	%	4.50	%		(a)
Ally Bank	18,975		17.89		17,888		16.70		4.50			6.50	%
Tier 1 (to risk-weighted assets)
Ally Financial Inc.	$	15,417	11.18	%	$	15,147	10.93	%	6.00	%		6.00	%
Ally Bank	18,975		17.89		17,888		16.70		6.00			8.00
Total (to risk-weighted assets)
Ally Financial Inc.	$	17,704	12.83	%	$	17,419	12.57	%	8.00	%		10.00	%
Ally Bank	19,651		18.53		18,458		17.24		8.00			10.00
Tier 1 leverage (to adjusted quarterly average assets) (b)
Ally Financial Inc.	$	15,417	9.51	%	$	15,147	9.54	%	4.00	%		(a)
Ally Bank	18,975		15.31		17,888		15.21		15.00		(c)	5.00	%

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

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

(c) Ally Bank has committed to the FRB to maintain a Tier 1 leverage ratio of at least 15%.