Stockholders' Equity - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Millions |
3 Months Ended | 9 Months Ended | |||||
|---|---|---|---|---|---|---|---|
Jun. 30, 2020 |
Jun. 30, 2019 |
Jun. 30, 2020 |
Jun. 30, 2019 |
Jul. 20, 2020 |
Jan. 31, 2020 |
Jan. 31, 2019 |
|
| Stockholders Equity Note [Line Items] | |||||||
| Share repurchase program | $ 9,500 | $ 8,500 | |||||
| January 2020 share repurchase program remaining authorized funds | $ 7,000 | $ 7,000 | |||||
| Cash dividends declared and paid, at a quarterly amount per Class A share | $ 663 | $ 565 | $ 2,002 | $ 1,706 | |||
| Subsequent Event | Class A common stock | |||||||
| Stockholders Equity Note [Line Items] | |||||||
| Quarterly cash dividend (in dollars per share) | $ 0.30 | ||||||