Nature Of Operations and Basis of Presentation	12 Months Ended
Dec. 31, 2018
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 trucks, crossovers, cars and automobile parts worldwide and are investing in and growing an autonomous ride-sharing vehicle business. We also provide automotive financing services through GM Financial. We analyze the results of our continuing operations through the following segments: GMNA, GMI, GM Cruise and GM Financial. GM Cruise is our global segment responsible for the development and commercialization of autonomous vehicle technology. As a result of the growing importance of our autonomous vehicle operations, we moved these operations from Corporate to GM Cruise and began presenting GM Cruise as a new reportable segment in 2018. All periods presented have been recast to reflect the segment changes. 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 and certain nonsegment specific revenues and expenses. On July 31, 2017 we closed the sale of the Opel/Vauxhall Business to PSA Group. On October 31, 2017 we closed the sale of the Fincos 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. Unless otherwise indicated, information in this report relates to our continuing operations. Refer to Note 22 for additional information on our discontinued operations. In 2018 we changed the presentation of our consolidated statements of cash flows to separately classify Depreciation and impairment of Equipment on operating leases, net and Depreciation, amortization and impairment charges on Property, net. We have made corresponding reclassifications to the comparable information for all periods presented. 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 are the primary beneficiary. 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. Beginning January 1, 2018 we no longer use the cost method of accounting due to the adoption of ASU 2016-01, "Recognition and Measurement of Financial Assets and Financial Liabilities" (ASU 2016-01). Refer to Note 2 for additional information on recently adopted accounting standards. 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 trucks, crossovers, cars and automobile parts worldwide and are investing in and growing an autonomous ride-sharing vehicle business. We also provide automotive financing services through GM Financial. We analyze the results of our continuing operations through the following segments: GMNA, GMI, GM Cruise and GM Financial. GM Cruise is our global segment responsible for the development and commercialization of autonomous vehicle technology. As a result of the growing importance of our autonomous vehicle operations, we moved these operations from Corporate to GM Cruise and began presenting GM Cruise as a new reportable segment in 2018. All periods presented have been recast to reflect the segment changes. 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 and certain nonsegment specific revenues and expenses.

On July 31, 2017 we closed the sale of the Opel/Vauxhall Business to PSA Group. On October 31, 2017 we closed the sale of the Fincos 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. Unless otherwise indicated, information in this report relates to our continuing operations. Refer to Note 22 for additional information on our discontinued operations.

In 2018 we changed the presentation of our consolidated statements of cash flows to separately classify Depreciation and impairment of Equipment on operating leases, net and Depreciation, amortization and impairment charges on Property, net. We have made corresponding reclassifications to the comparable information for all periods presented.

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 are the primary beneficiary. 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. Beginning January 1, 2018 we no longer use the cost method of accounting due to the adoption of ASU 2016-01, "Recognition and Measurement of Financial Assets and Financial Liabilities" (ASU 2016-01). Refer to Note 2 for additional information on recently adopted accounting standards.

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.