Stockholders' Equity - Additional Information (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions |
1 Months Ended | 3 Months Ended | 6 Months Ended | |||||
|---|---|---|---|---|---|---|---|---|
May 31, 2024 |
Mar. 31, 2025 |
Mar. 31, 2024 |
Mar. 31, 2025 |
Mar. 31, 2024 |
Apr. 30, 2025 |
Apr. 29, 2025 |
Oct. 31, 2023 |
|
| Equity, Class of Treasury Stock [Line Items] | ||||||||
| Share repurchase program | $ 25,000 | |||||||
| Share repurchase programs authorized | $ 4,700 | $ 4,700 | ||||||
| Dividends paid | $ 1,164 | $ 1,060 | $ 2,300 | $ 2,100 | ||||
| Class B-1 common stock | ||||||||
| Equity, Class of Treasury Stock [Line Items] | ||||||||
| Stock tendered during period, shares, stock exchange offer (in shares) | 241 | |||||||
| Class B-2 common stock | ||||||||
| Equity, Class of Treasury Stock [Line Items] | ||||||||
| Stock issued during the period, new issues (in shares) | 120 | |||||||
| Class C common stock | ||||||||
| Equity, Class of Treasury Stock [Line Items] | ||||||||
| Stock issued during the period, new issues (in shares) | 48 | |||||||
| Subsequent Event | ||||||||
| Equity, Class of Treasury Stock [Line Items] | ||||||||
| Share repurchase program | $ 30,000 | |||||||
| Quarterly cash dividend (in dollars per share) | $ 0.59 | |||||||