CASH AND CASH EQUIVALENTS, FUNDS RECEIVABLE AND CUSTOMER ACCOUNTS, AND INVESTMENTS - Schedule of Cumulative Gross Unrealized Gains and Cumulative Gross Unrealized Losses and Impairment Related to Non-marketable Equity Securities (Details) - USD ($) $ in Millions |
Mar. 31, 2026 |
Dec. 31, 2025 |
|---|---|---|
| Investments, Debt and Equity Securities [Abstract] | ||
| Cumulative gross unrealized gains | $ 917 | $ 872 |
| Cumulative gross unrealized losses and impairments | $ (421) | $ (353) |