Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021
Cash flows from operating activities:
Net income	$ 111,119	$ 86,459
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization expense	41,993	37,159
Stock-based compensation expense	36,750	28,796
Amortization of operating lease right-of-use assets	17,365	20,012
Unrealized (gain)/loss on investments	(475)	5,987
Unrealized foreign currency exchange gain, net	(16,813)	(3,799)
Deferred income tax benefit	(5,621)	(17,374)
Allowance / (reversal) of expected credit losses	177	(405)
Fair value changes in contingent consideration	1,000	0
Loss on settlement of convertible notes	0	12,845
Amortization of non-cash interest expense related to convertible senior notes	0	1,795
Others, net	1,240	590
Change in operating assets and liabilities, net of effects of acquisitions:
Accounts receivable	(68,066)	(44,871)
Other current assets	2,553	3,033
Income taxes payable, net	4,043	(5,685)
Other assets	(8,428)	2,485
Accounts payable	(1,927)	(2,333)
Deferred revenue	2,103	(21,196)
Accrued employee costs	(11,778)	26,664
Accrued expenses and other liabilities	13,685	3,254
Operating lease liabilities	(17,831)	(19,654)
Net cash provided by operating activities	101,089	113,762
Cash flows from investing activities:
Purchases of property and equipment	(32,099)	(29,026)
Proceeds from sale of property and equipment	197	825
Business acquisition (net of cash and cash equivalents acquired)	(3,322)	0
Purchases of investments	(164,313)	(76,500)
Proceeds from redemption of investments	124,355	83,183
Net cash used for investing activities	(75,182)	(21,518)
Cash flows from financing activities:
Principal payments of finance lease liabilities	(108)	(157)
Proceeds from borrowings	35,000	225,000
Repayments of borrowings	(25,000)	(329,000)
Acquisition of treasury stock	(71,712)	(85,620)
Proceeds from exercise of stock options	0	710
Net cash used for financing activities	(61,820)	(189,067)
Effect of exchange rate changes on cash, cash equivalents and restricted cash	(9,626)	(5,003)
Net decrease in cash, cash equivalents and restricted cash	(45,539)	(101,826)
Cash, cash equivalents and restricted cash at the beginning of the period	143,810	225,519
Cash, cash equivalents and restricted cash at the end of the period	98,271	123,693
Cash paid during the period for:
Interest	4,982	5,833
Income taxes, net of refunds	35,192	31,087
Supplemental disclosure of non-cash investing and financing activities:
Settlement of portion of convertible notes through issuance of treasury stock	0	36,742
Assets acquired under finance lease	$ 218	$ 79