FAIR VALUE MEASUREMENT OF ASSETS AND LIABILITIES - Summary of Investments Under the Fair Value Option (Details) - USD ($) $ in Millions |
3 Months Ended | 6 Months Ended | |||
|---|---|---|---|---|---|
Jun. 30, 2023 |
Jun. 30, 2022 |
Jun. 30, 2023 |
Jun. 30, 2022 |
Dec. 31, 2022 |
|
| Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | |||||
| Debt securities, available-for-sale, amortized cost, excluding accrued interest, after allowance for credit loss | $ 22,535 | $ 22,535 | $ 22,869 | ||
| Debt securities, available-for-sale, excluding accrued interest | 22,132 | 22,132 | 22,278 | ||
| Fair Value Option, Investments | Funds receivable and customer accounts | |||||
| Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | |||||
| Debt securities, available-for-sale, amortized cost, excluding accrued interest, after allowance for credit loss | 442 | 442 | 441 | ||
| Debt securities, available-for-sale, excluding accrued interest | 504 | 504 | $ 481 | ||
| Net gains (losses) from fair value changes | $ 4 | $ (109) | $ 11 | $ (143) | |