Nature Of Operations and Basis of Presentation	12 Months Ended
Dec. 31, 2017
Nature of Operations and Basis of Presentation [Abstract]
Nature of Operations and Basis of Presentation	Nature of Operations and Basis of Presentation General Motors Company was incorporated as a Delaware corporation in 2009. We design, build and sell cars, trucks, crossovers and automobile parts worldwide. We also provide automotive financing services through GM Financial. We analyze the results of our continuing operations through the following segments: GMNA, GMI and GM Financial. Nonsegment operations and Maven, our ride- and car-sharing business, are classified as Corporate. Corporate includes certain centrally recorded income and costs such as interest, income taxes, corporate expenditures including autonomous vehicle-related engineering costs and certain nonsegment specific revenues and expenses. On July 31, 2017 we closed the sale of our Opel and Vauxhall businesses and certain other assets in Europe (the Opel/Vauxhall Business) to Peugeot, S.A. (PSA Group). On October 31, 2017 we closed the sale of our European financing subsidiaries and branches (the Fincos, and together with the Opel/Vauxhall Business, the European Business) to Banque PSA Finance S.A. and BNP Paribas Personal Finance S.A. The European Business is presented as discontinued operations in our consolidated financial statements for all periods presented. The assets and liabilities of the European Business are presented as held for sale in our consolidated financial statements as of December 31, 2016. Unless otherwise indicated, information in these notes to the consolidated financial statements relates to our continuing operations. Refer to Note 3 for additional details regarding the disposal of the European Business. Principles of Consolidation The consolidated financial statements are prepared in conformity with U.S. GAAP. All intercompany balances and transactions have been eliminated in consolidation. Except for per share amounts or as otherwise specified, amounts presented within tables are stated in millions. We consolidate entities that we control due to ownership of a majority voting interest and we consolidate variable interest entities (VIEs) when we have variable interests and are the primary beneficiary. We continually evaluate our involvement with VIEs to determine when these criteria are met. Our share of earnings or losses of nonconsolidated affiliates is included in our consolidated operating results using the equity method of accounting when we are able to exercise significant influence over the operating and financial decisions of the affiliate. We use the cost method of accounting if we are not able to exercise significant influence over the operating and financial decisions of the affiliate. Use of Estimates in the Preparation of the Financial Statements Accounting estimates are an integral part of the consolidated financial statements. These estimates require the use of judgments and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses in the periods presented. We believe that the accounting estimates employed are appropriate and the resulting balances are reasonable; however, due to the inherent uncertainties in making estimates, actual results could differ from the original estimates, requiring adjustments to these balances in future periods. GM Financial The amounts presented for GM Financial have been adjusted to include the effect of our tax attributes on GM Financial's deferred tax positions and provision for income taxes, which are not applicable to GM Financial on a stand-alone basis, and to eliminate the effect of transactions between GM Financial and the other members of the consolidated group. Accordingly, the amounts presented will differ from those presented by GM Financial on a stand-alone basis.

Nature of Operations and Basis of Presentation

General Motors Company was incorporated as a Delaware corporation in 2009. We design, build and sell cars, trucks, crossovers and automobile parts worldwide. We also provide automotive financing services through GM Financial. We analyze the results of our continuing operations through the following segments: GMNA, GMI and GM Financial. Nonsegment operations and Maven, our ride- and car-sharing business, are classified as Corporate. Corporate includes certain centrally recorded income and costs such as interest, income taxes, corporate expenditures including autonomous vehicle-related engineering costs and certain nonsegment specific revenues and expenses.

On July 31, 2017 we closed the sale of our Opel and Vauxhall businesses and certain other assets in Europe (the Opel/Vauxhall Business) to Peugeot, S.A. (PSA Group). On October 31, 2017 we closed the sale of our European financing subsidiaries and branches (the Fincos, and together with the Opel/Vauxhall Business, the European Business) to Banque PSA Finance S.A. and BNP Paribas Personal Finance S.A. The European Business is presented as discontinued operations in our consolidated financial statements for all periods presented. The assets and liabilities of the European Business are presented as held for sale in our consolidated financial statements as of December 31, 2016. Unless otherwise indicated, information in these notes to the consolidated financial statements relates to our continuing operations. Refer to Note 3 for additional details regarding the disposal of the European Business.

Principles of Consolidation The consolidated financial statements are prepared in conformity with U.S. GAAP. All intercompany balances and transactions have been eliminated in consolidation. Except for per share amounts or as otherwise specified, amounts presented within tables are stated in millions.

We consolidate entities that we control due to ownership of a majority voting interest and we consolidate variable interest entities (VIEs) when we have variable interests and are the primary beneficiary. We continually evaluate our involvement with VIEs to determine when these criteria are met. Our share of earnings or losses of nonconsolidated affiliates is included in our consolidated operating results using the equity method of accounting when we are able to exercise significant influence over the operating and financial decisions of the affiliate. We use the cost method of accounting if we are not able to exercise significant influence over the operating and financial decisions of the affiliate.

Use of Estimates in the Preparation of the Financial Statements Accounting estimates are an integral part of the consolidated financial statements. These estimates require the use of judgments and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses in the periods presented. We believe that the accounting estimates employed are appropriate and the resulting balances are reasonable; however, due to the inherent uncertainties in making estimates, actual results could differ from the original estimates, requiring adjustments to these balances in future periods.

GM Financial The amounts presented for GM Financial have been adjusted to include the effect of our tax attributes on GM Financial's deferred tax positions and provision for income taxes, which are not applicable to GM Financial on a stand-alone basis, and to eliminate the effect of transactions between GM Financial and the other members of the consolidated group. Accordingly, the amounts presented will differ from those presented by GM Financial on a stand-alone basis.