Subsequent Events (Details) - USD ($) $ in Millions |
1 Months Ended | |||
|---|---|---|---|---|
Jan. 31, 2021 |
Feb. 10, 2021 |
Dec. 31, 2020 |
Dec. 31, 2019 |
|
| Subsequent Event [Line Items] | ||||
| Deferred tax assets valuation allowance | $ 9,095 | $ 8,135 | ||
| Subsequent Event | GM Cruise | ||||
| Subsequent Event [Line Items] | ||||
| Deferred tax assets valuation allowance | $ 350 | |||
| Subsequent Event | Series G Preferred Shares | GM Cruise | Microsoft and other investors | ||||
| Subsequent Event [Line Items] | ||||
| Proceeds from sale of stock | $ 2,200 | |||
| Subsequent Event | Series G Preferred Shares | GM Cruise | General Motors Holdings LLC | ||||
| Subsequent Event [Line Items] | ||||
| Proceeds from sale of stock | $ 1,000 |