CUSTOMER FUNDS AND INVESTMENTS - Available-for-sale debt securities (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2025 USD ($)
Available-for-sale debt securities
One year or less	$ 349,942
After one year through five years	937,883
U.S. treasury securities
Available-for-sale debt securities
Gross unrealized gains, net of tax	8,126
Gross unrealized loss, net of tax	126
Less than 12 months, Gross Unrealized Losses	161
Less than 12 months, Fair Value	$ 70,543