Unaudited Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023
Cash flows from operating activities
Net income	$ 388,435	$ 259,031
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	106,158	82,959
Accretion of discount on available-for-sale securities	(112)	(387)
Non-cash marketing expense	1,202	1,263
Gain on disposition of property and equipment	(12)	(33)
Amortization of debt issuance costs	831	946
Stock-based compensation expense	(45,514)	96,383
Loss on extinguishment of debt		1,222
Deferred income taxes, net	(3,827)	3,889
Other	(97)	18
Changes in operating assets and liabilities:
Accounts receivable	(4,134)	7,295
Prepaid expenses	(7,970)	(8,845)
Inventory	869	375
Other assets	(1,657)	(8,262)
Deferred contract costs	(84,413)	(87,604)
Accounts payable	13,088	(8,131)
Income taxes, net	8,050	(5,187)
Accrued commissions and bonuses	(7,115)	(8,016)
Accrued payroll and vacation	(6,591)	(3,863)
Deferred revenue	11,787	10,902
Net change in operating right-of-use assets and operating lease liabilities	639	882
Accrued expenses and other current liabilities	3,896	15,732
Net cash provided by operating activities	373,513	350,569
Cash flows from investing activities
Purchases of investments from funds held for clients	(24,926)	(25,000)
Proceeds from investments from funds held for clients	200,000	25,000
Purchases of property and equipment	(141,549)	(135,709)
Proceeds from sale of property and equipment	13	67
Net cash provided by (used in) investing activities	33,538	(135,642)
Cash flows from financing activities
Repurchases of common stock	(122,801)	(74,994)
Withholding taxes paid related to net share settlements	(14,415)	(12,620)
Dividends paid	(63,687)	(43,367)
Net change in client funds obligation	(888,428)	(306,063)
Payment of debt issuance costs		(649)
Net cash used in financing activities	(1,089,331)	(437,693)
Decrease in cash, cash equivalents, restricted cash and restricted cash equivalents	(682,280)	(222,766)
Cash, cash equivalents, restricted cash and restricted cash equivalents
Cash, cash equivalents, restricted cash and restricted cash equivalents, beginning of period	2,422,760	2,409,095
Cash, cash equivalents, restricted cash and restricted cash equivalents, end of period	1,740,480	2,186,329
Cash and cash equivalents	325,757	484,028
Restricted cash included in funds held for clients	1,414,723	1,702,301
Total cash, cash equivalents, restricted cash and restricted cash equivalents, end of period	1,740,480	2,186,329
Non-cash investing and financing activities:
Purchases of property and equipment, accrued but not paid	3,640	8,011
Stock-based compensation for capitalized software	13,850	11,529
Right of use assets obtained in exchange for operating lease liabilities	$ 17,507	$ 21,023