Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) or earnings per unit (EPU) in the future that were not included in the computation of diluted EPS or EPU because to do so would increase EPS or EPU amounts or decrease loss per share or unit amounts for the period presented.

Name:	us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Per basic share amount, after tax, of income (loss) from the day-to-day business activities of the discontinued operation.

+ References

No definition available.

Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Basic Earnings per Common Share
Income from continuing operations									$ 348	$ 9,428	$ 9,662
Less: cumulative dividends on GM Financial preferred stock									(16)	0	0
Income from continuing operations attributable to common stockholders									332	9,428	9,662
Income (loss) from discontinued operations, net of tax									(4,212)	(1)	25
Net income (loss) attributable to common stockholders									$ (3,880)	$ 9,427	$ 9,687
Weighted-average common shares outstanding - basic (in shares)									1,465	1,540	1,586
Basic earnings per common share – continuing operations (in dollars per share)	$ (3.46)	$ 0.08	$ 1.62	$ 1.78	$ 1.29	$ 1.79	$ 1.78	$ 1.25	$ 0.23	$ 6.12	$ 6.09
Basic earnings (loss) per common share – discontinued operations (in dollars per share)	(0.19)	(2.14)	(0.51)	(0.05)	(0.08)	0.00	0.07	0.01	(2.88)	0.00	0.02
Basic earnings (loss) per common share (in dollars per share)									$ (2.65)	$ 6.12	$ 6.11
Diluted earnings per share
Income from continuing operations attributable to common stockholders – diluted									$ 332	$ 9,428	$ 9,661
Income (loss) from discontinued operations, net of tax – diluted									(4,212)	(1)	25
Net income (loss) attributable to common stockholders – diluted									$ (3,880)	$ 9,427	$ 9,686
Weighted-average common shares outstanding - basic (in shares)									1,465	1,540	1,586
Dilutive effect of warrants and awards under stock incentive plans (in shares)									27	30	54
Weighted-average common shares outstanding – diluted (in shares)									1,492	1,570	1,640
Diluted earnings per common share – continuing operations (in dollars per share)	(3.46)	0.08	1.60	1.75	1.27	1.76	1.74	1.23	$ 0.22	$ 6.00	$ 5.89
Diluted earnings (loss) per common share – discontinued operations (in dollars per share)	$ (0.19)	$ (2.11)	$ (0.51)	$ (0.05)	$ (0.08)	$ 0.00	$ 0.07	$ 0.01	(2.82)	0.00	0.02
Diluted earnings (loss) per common share (in dollars per share)									$ (2.60)	$ 6.00	$ 5.91
Potentially dilutive securities (in shares)									0	0	72