Stockholders' Equity - Effect of VE Territory Covered Losses Through Conversion Rate Adjustments (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions |
3 Months Ended | 9 Months Ended | ||
|---|---|---|---|---|
Jun. 30, 2023 |
Jun. 30, 2022 |
Jun. 30, 2023 |
Jun. 30, 2022 |
|
| Conversion of Stock [Line Items] | ||||
| Recovery through conversion rate adjustment | $ 0 | $ 0 | $ 1 | $ 0 |
| Series B preferred stock | ||||
| Conversion of Stock [Line Items] | ||||
| Reduction in equivalent number of class A common stock (in shares) | 0 | 1 | ||
| Effective price per share (in dollars per share) | $ 219.12 | $ 203.08 | ||
| Recovery through conversion rate adjustment | $ 19 | $ 135 | ||
| Series C preferred stock | ||||
| Conversion of Stock [Line Items] | ||||
| Reduction in equivalent number of class A common stock (in shares) | 0 | 0 | ||
| Effective price per share (in dollars per share) | $ 215.28 | $ 202.55 | ||
| Recovery through conversion rate adjustment | $ 11 | $ 6 | ||