Automotive and GM Financial Debt (Details) - USD ($) $ in Millions |
Mar. 31, 2017 |
Dec. 31, 2016 |
|---|---|---|
| Automotive [Member] | ||
| Debt Instrument [Line Items] | ||
| Carrying Amount | $ 10,952 | $ 10,752 |
| Fair Value | 11,913 | 11,612 |
| Automotive [Member] | Level 1 [Member] | ||
| Debt Instrument [Line Items] | ||
| Fair Value | 9,590 | 9,515 |
| Automotive [Member] | Level 2 [Member] | ||
| Debt Instrument [Line Items] | ||
| Fair Value | 2,323 | 2,097 |
| GM Financial [Member] | ||
| Debt Instrument [Line Items] | ||
| Carrying Amount | 79,949 | 73,876 |
| Fair Value | 81,070 | 74,577 |
| GM Financial [Member] | Secured Debt [Member] | ||
| Debt Instrument [Line Items] | ||
| Carrying Amount | 42,579 | 39,270 |
| Fair Value | 42,680 | 39,357 |
| GM Financial [Member] | Unsecured Debt [Member] | ||
| Debt Instrument [Line Items] | ||
| Carrying Amount | 37,370 | 34,606 |
| Fair Value | 38,390 | 35,220 |
| GM Financial [Member] | Level 2 [Member] | ||
| Debt Instrument [Line Items] | ||
| Fair Value | 77,267 | 69,990 |
| GM Financial [Member] | Level 3 [Member] | ||
| Debt Instrument [Line Items] | ||
| Fair Value | $ 3,803 | $ 4,587 |