Unaudited Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Cash flows from operating activities
Net income	$ 259,031	$ 201,438
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	82,959	67,783
Accretion of discount on available-for-sale securities	(387)	(872)
Non-cash marketing expense	1,263	1,320
Gain on disposition of property and equipment	(33)
Amortization of debt issuance costs	946	532
Stock-based compensation expense	96,383	70,815
Loss on extinguishment of debt	1,222
Cash paid for derivative settlement		205
Gain on derivative		(1,559)
Deferred income taxes, net	3,889	(4,841)
Other	18	(227)
Changes in operating assets and liabilities:
Accounts receivable	7,295	(5,406)
Prepaid expenses	(8,845)	(11,203)
Inventory	375	27
Other assets	(15,773)	(10,104)
Deferred contract costs	(87,604)	(86,634)
Accounts payable	(8,131)	4,159
Income taxes, net	(5,187)	1,245
Accrued commissions and bonuses	(8,016)	(3,320)
Accrued payroll and vacation	(3,863)	1,810
Deferred revenue	10,902	12,585
Accrued expenses and other current liabilities	24,125	(1,106)
Net cash provided by operating activities	350,569	236,647
Cash flows from investing activities
Purchases of investments from funds held for clients	(25,000)	(268,718)
Proceeds from investments from funds held for clients	25,000	328,731
Purchases of property and equipment	(135,709)	(92,041)
Proceeds from sale of property and equipment	67
Net cash used in investing activities	(135,642)	(32,028)
Cash flows from financing activities
Proceeds from the issuance of debt		29,000
Repurchases of common stock	(74,994)	(94,652)
Withholding taxes paid related to net share settlements	(12,620)	(5,017)
Payments on long-term debt		(29,287)
Dividends paid	(43,367)
Net change in client funds obligation	(306,063)	(92,478)
Payment of debt issuance costs	(649)	(6,437)
Net cash used in financing activities	(437,693)	(198,871)
(Decrease) increase in cash, cash equivalents, restricted cash and restricted cash equivalents	(222,766)	5,748
Cash, cash equivalents, restricted cash and restricted cash equivalents
Cash, cash equivalents, restricted cash and restricted cash equivalents, beginning of period	2,409,095	1,812,691
Cash, cash equivalents, restricted cash and restricted cash equivalents, end of period	2,186,329	1,818,439
Cash and cash equivalents	484,028	317,163
Restricted cash included in funds held for clients	1,702,301	1,501,276
Total cash, cash equivalents, restricted cash and restricted cash equivalents, end of period	2,186,329	1,818,439
Non-cash investing and financing activities:
Purchases of property and equipment, accrued but not paid	8,011	3,355
Stock-based compensation for capitalized software	11,529	6,545
Right of use assets obtained in exchange for operating lease liabilities	$ 21,023	$ 14,385