SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Stock-Based Compensation (Details) - USD ($) $ in Millions |
3 Months Ended | |
|---|---|---|
Mar. 31, 2026 |
Mar. 31, 2025 |
|
| Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items] | ||
| Stock-based compensation expense | $ 42 | $ 30 |
| Cost of revenue | ||
| Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items] | ||
| Stock-based compensation expense | 6 | 4 |
| Selling and marketing (excluding customer base amortization) | ||
| Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items] | ||
| Stock-based compensation expense | 5 | 5 |
| Software development | ||
| Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items] | ||
| Stock-based compensation expense | 13 | 7 |
| General and administrative | ||
| Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items] | ||
| Stock-based compensation expense | $ 18 | $ 14 |