Summary of Significant Accounting Policies - Allowance for Sales Returns (Details) - USD ($) $ in Millions |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2021 |
Dec. 31, 2020 |
Dec. 31, 2019 |
|
| Sales returns, beginning balance | $ 300 | $ 261 | $ 266 |
| Additions, charged to earnings | 2,145 | 2,188 | 2,336 |
| Deductions | (2,171) | (2,149) | (2,341) |
| Sales returns, ending balance | 274 | 300 | 261 |
| Stock-based compensation | 72 | 64 | 71 |
| Selling, General and Administrative Expenses | |||
| Advertising Expense | $ 560 | $ 440 | $ 395 |