FAIR VALUE MEASUREMENTS - Financial Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Thousands | Mar. 31, 2024 | Dec. 31, 2023 |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Customer funds | $ 4,046,346 | $ 3,170,430 |
Bitcoin investment | | 339,898 |
Safeguarding asset related to bitcoin held for other parties | 1,681,111 | 1,038,585 |
Safeguarding obligation liability related to bitcoin held for other parties | (1,681,111) | (1,038,585) |
Fair Value, Measurements, Recurring | Level 1 | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Investment in marketable equity securities | 1,610 | 8,267 |
Bitcoin investment | 573,302 | 339,898 |
Safeguarding asset related to bitcoin held for other parties | 0 | 0 |
Safeguarding obligation liability related to bitcoin held for other parties | 0 | 0 |
Total assets (liabilities) measured at fair value | 3,711,722 | 3,356,213 |
Fair Value, Measurements, Recurring | Level 1 | Money market funds | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Cash equivalents | 1,403,811 | 960,705 |
Restricted cash | 292,184 | 291,374 |
Customer funds | 4,645 | 4,042 |
Fair Value, Measurements, Recurring | Level 1 | U.S. government securities | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Cash equivalents | 44,577 | 29,788 |
Short-term debt securities | 370,063 | 539,998 |
Long-term debt securities | 89,146 | 153,387 |
Fair Value, Measurements, Recurring | Level 1 | U.S. agency securities | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Short-term debt securities | 0 | 0 |
Fair Value, Measurements, Recurring | Level 1 | Commercial paper | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Cash equivalents | 0 | 0 |
Fair Value, Measurements, Recurring | Level 1 | Corporate bonds | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Cash equivalents | 0 | 0 |
Short-term debt securities | 0 | 0 |
Long-term debt securities | 0 | 0 |
Fair Value, Measurements, Recurring | Level 1 | Reverse repurchase agreement | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Customer funds | 932,384 | 1,028,754 |
Fair Value, Measurements, Recurring | Level 1 | Certificates of deposit | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Short-term debt securities | 0 | 0 |
Fair Value, Measurements, Recurring | Level 1 | Commercial paper | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Short-term debt securities | 0 | 0 |
Fair Value, Measurements, Recurring | Level 1 | Municipal securities | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Short-term debt securities | 0 | 0 |
Long-term debt securities | 0 | 0 |
Fair Value, Measurements, Recurring | Level 1 | Foreign government securities | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Short-term debt securities | 0 | 0 |
Fair Value, Measurements, Recurring | Level 2 | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Investment in marketable equity securities | 0 | 0 |
Bitcoin investment | 0 | 0 |
Safeguarding asset related to bitcoin held for other parties | 1,681,111 | 1,038,585 |
Safeguarding obligation liability related to bitcoin held for other parties | (1,681,111) | (1,038,585) |
Total assets (liabilities) measured at fair value | 304,533 | 415,335 |
Fair Value, Measurements, Recurring | Level 2 | Money market funds | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Cash equivalents | 0 | 0 |
Restricted cash | 0 | 0 |
Customer funds | 0 | 0 |
Fair Value, Measurements, Recurring | Level 2 | U.S. government securities | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Cash equivalents | 0 | 0 |
Short-term debt securities | 0 | 0 |
Long-term debt securities | 0 | 0 |
Fair Value, Measurements, Recurring | Level 2 | U.S. agency securities | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Short-term debt securities | 57,722 | 67,515 |
Fair Value, Measurements, Recurring | Level 2 | Commercial paper | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Cash equivalents | 1,875 | 4,993 |
Fair Value, Measurements, Recurring | Level 2 | Corporate bonds | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Cash equivalents | 555 | 699 |
Short-term debt securities | 134,532 | 215,227 |
Long-term debt securities | 96,384 | 95,328 |
Fair Value, Measurements, Recurring | Level 2 | Reverse repurchase agreement | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Customer funds | 0 | 0 |
Fair Value, Measurements, Recurring | Level 2 | Certificates of deposit | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Short-term debt securities | 500 | 3,856 |
Fair Value, Measurements, Recurring | Level 2 | Commercial paper | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Short-term debt securities | 724 | 15,159 |
Fair Value, Measurements, Recurring | Level 2 | Municipal securities | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Short-term debt securities | 9,253 | 9,165 |
Long-term debt securities | 2,392 | 2,412 |
Fair Value, Measurements, Recurring | Level 2 | Foreign government securities | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Short-term debt securities | 596 | 981 |
Fair Value, Measurements, Recurring | Level 3 | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Investment in marketable equity securities | 0 | 0 |
Bitcoin investment | 0 | 0 |
Safeguarding asset related to bitcoin held for other parties | 0 | 0 |
Safeguarding obligation liability related to bitcoin held for other parties | 0 | 0 |
Total assets (liabilities) measured at fair value | 0 | 0 |
Fair Value, Measurements, Recurring | Level 3 | Money market funds | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Cash equivalents | 0 | 0 |
Restricted cash | 0 | 0 |
Customer funds | 0 | 0 |
Fair Value, Measurements, Recurring | Level 3 | U.S. government securities | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Cash equivalents | 0 | 0 |
Short-term debt securities | 0 | 0 |
Long-term debt securities | 0 | 0 |
Fair Value, Measurements, Recurring | Level 3 | U.S. agency securities | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Short-term debt securities | 0 | 0 |
Fair Value, Measurements, Recurring | Level 3 | Commercial paper | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Cash equivalents | 0 | 0 |
Fair Value, Measurements, Recurring | Level 3 | Corporate bonds | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Cash equivalents | 0 | 0 |
Short-term debt securities | 0 | 0 |
Long-term debt securities | 0 | 0 |
Fair Value, Measurements, Recurring | Level 3 | Reverse repurchase agreement | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Customer funds | 0 | 0 |
Fair Value, Measurements, Recurring | Level 3 | Certificates of deposit | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Short-term debt securities | 0 | 0 |
Fair Value, Measurements, Recurring | Level 3 | Commercial paper | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Short-term debt securities | 0 | 0 |
Fair Value, Measurements, Recurring | Level 3 | Municipal securities | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Short-term debt securities | 0 | 0 |
Long-term debt securities | 0 | 0 |
Fair Value, Measurements, Recurring | Level 3 | Foreign government securities | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Short-term debt securities | $ 0 | $ 0 |