CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023
Cash flows from operating activities:
Net income	$ 351,234	$ 319,529
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization expense	63,003	68,642
Operating lease right-of-use assets amortization expense	28,051	30,842
Bad debt (recovery)/expense	(3,071)	2,739
Deferred taxes	(24,888)	(11,760)
Stock-based compensation expense	122,599	109,536
Unrealized gain on derivative instruments	0	(7,904)
Impairment charges	395	688
Loss on sale of business	0	25,922
Other	6,715	1,106
Changes in assets and liabilities:
Trade receivables and contract assets	(22,791)	6,145
Prepaid and other assets	(52,167)	13,208
Accounts payable	(4,611)	837
Accrued expenses and other liabilities	17,262	(95,570)
Operating lease liabilities	(29,604)	(34,310)
Income taxes payable	(23,218)	(38,385)
Net cash provided by operating activities	428,909	391,265
Cash flows from investing activities:
Purchases of property and equipment	(16,419)	(18,420)
Purchases of short-term investments	(1,872)	(10,865)
Proceeds from short-term investments	41,509	10,865
Acquisition of business, net of cash acquired (Note 3)	(57,065)	(13,997)
Cash sold as part of sale of business, net of proceeds	0	(2,169)
Purchases of non-marketable securities	(6,927)	(3,281)
Other investing activities, net	1,674	(8,204)
Net cash used in investing activities	(39,100)	(46,071)
Cash flows from financing activities:
Proceeds from issuance of stock under the employee incentive programs	33,781	28,612
Payments of withholding taxes related to net share settlements of restricted stock units	(32,465)	(28,202)
Proceeds from debt	0	764
Repayment of debt	(1,497)	(2,607)
Repurchase of common stock	(385,025)	(128,433)
Payment of contingent consideration for previously acquired business	(4,750)	(8,684)
Purchase of subsidiary shares from noncontrolling interest	0	(1,972)
Other financing activities, net	(1,711)	(2,895)
Net cash used in financing activities	(391,667)	(143,417)
Effect of exchange rate changes on cash, cash equivalents and restricted cash	(543)	(5,632)
Net (decrease)/increase in cash, cash equivalents and restricted cash	(2,401)	196,145
Cash, cash equivalents and restricted cash, beginning of period	2,043,108	1,683,636
Cash, cash equivalents and restricted cash, end of period	$ 2,040,707	$ 1,879,781