Investments (Equity Securities) (Details Textual) - USD ($) $ in Millions |
3 Months Ended | 9 Months Ended | |||
|---|---|---|---|---|---|
Sep. 30, 2021 |
Sep. 30, 2020 |
Sep. 30, 2021 |
Sep. 30, 2020 |
Dec. 31, 2020 |
|
| Debt Securities, Available-for-sale [Line Items] | |||||
| Equity securities | $ 865 | $ 865 | $ 477 | ||
| Equity Securities, FV-NI, Unrealized Gain (Loss) | 135 | $ 60 | 104 | $ 65 | |
| Equity securities without readily determinable fair value | 255 | 255 | 203 | ||
| Equity Securities without Readily Determinable Fair Value, Upward Price Adjustment, Annual Amount | 94 | $ 12 | 129 | $ 20 | |
| Fair Value, Inputs, Level 1 [Member] | |||||
| Debt Securities, Available-for-sale [Line Items] | |||||
| Equity securities | $ 608 | $ 608 | $ 477 | ||