v2.4.0.6

Pensions And Other Postretirement Benefits Pension and OPEB (Tables) | 3 Months Ended
--- | ---
Mar. 31, 2012
Plan Contributions [Abstract] |
Components of Net Periodic Pension and OPEB Expense with Assumptions [Table Text Block] | The following tables summarize the components of net periodic pension and other postretirement benefits (OPEB) (income) expense (dollars in millions):
| Three Months Ended March 31, 2012
| U.S. Plans Pension Benefits |  | Non-U.S. Plans Pension Benefits |  | U.S. Plans Other Benefits |  | Non-U.S. Plans Other Benefits
Service cost | $ | 160 |  |  | $ | 92 |  |  | $ | 5 |  |  | $ | 5 |
Interest cost | 1,080 |  |  | 277 |  |  | 59 |  |  | 16 |
Expected return on plan assets | (1,332 | ) |  | (217 | ) |  | — |  |  | — |
Amortization of prior service credit | — |  |  | — |  |  | (29 | ) |  | (2 | )
Recognized net actuarial loss | — |  |  | 8 |  |  | 13 |  |  | 1 |
Curtailments, settlements, and other (gains) losses | (21 | ) |  | 28 |  |  | — |  |  | — |
Net periodic pension and OPEB (income) expense | $ | (113 | ) |  | $ | 188 |  |  | $ | 48 |  |  | $ | 20 |
| Three Months Ended March 31, 2011
| U.S. Plans Pension Benefits |  | Non-U.S. Plans Pension Benefits |  | U.S. Plans Other Benefits |  | Non-U.S. Plans Other Benefits
Service cost | $ | 158 |  |  | $ | 96 |  |  | $ | 6 |  |  | $ | 9 |
Interest cost | 1,229 |  |  | 301 |  |  | 67 |  |  | 52 |
Expected return on plan assets | (1,674 | ) |  | (230 | ) |  | — |  |  | — |
Amortization of prior service credit | — |  |  | — |  |  | — |  |  | (2 | )
Recognition of net actuarial loss | — |  |  | — |  |  | 1 |  |  | — |
Curtailments, settlements, and other losses | — |  |  | 3 |  |  | — |  |  | — |
Net periodic pension and OPEB (income) expense | $ | (287 | ) |  | $ | 170 |  |  | $ | 74 |  |  | $ | 59 |

X
- Definition Components of Net Periodic Pension and OPEB Expense with Assumptions + References No definition available. + Details
Name: | gm_ComponentsOfNetPeriodicPensionAndOpebExpenseWithAssumptionsTableTextBlock
Namespace Prefix: | gm_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | gm_PlanContributionsAbstract
Namespace Prefix: | gm_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration