Investments and Fair Value Measurement - Unrealized Gain (Loss) on Non-Marketable Securities (Details) - USD ($) $ in Millions |
3 Months Ended | 12 Months Ended | ||
|---|---|---|---|---|
Mar. 31, 2020 |
Dec. 31, 2021 |
Dec. 31, 2020 |
Dec. 31, 2019 |
|
| Fair Value Disclosures [Abstract] | ||||
| Upward adjustments | $ 71 | $ 0 | $ 0 | |
| Downward adjustments (including impairment) | $ (1,700) | 0 | (1,690) | 0 |
| Total unrealized gain (loss) for non-marketable equity securities | $ 71 | $ (1,690) | $ 0 | |