Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Cash flows from operating activities:
Net income	$ 22,411	$ 14,695
Adjustments to reconcile net income to net cash (used for)/provided by operating activities:
Depreciation and amortization expense	12,472	13,724
Stock-based compensation expense	4,778	6,956
Amortization of operating lease right-of-use assets	6,853	7,017
Unrealized gain on short term investments	267	(3,185)
Unrealized foreign exchange (gain)/loss, net	(5,112)	127
Deferred income tax expense	3,539	1,049
Allowance for expected credit losses	195	298
Loss from equity-method investment	55	67
Amortization of non-cash interest expense related to convertible senior notes	635	600
Impairment charges	0	1,227
Others, net	(26)	(1,401)
Change in operating assets and liabilities:
Accounts receivable	(17,518)	(12,016)
Prepaid expenses and other current assets	(3,249)	591
Advance income tax, net	(1,109)	(2,099)
Other assets	925	388
Accounts payable	1,400	(1,159)
Deferred revenue	2,579	3,262
Accrued employee costs	(37,046)	(22,436)
Accrued expenses and other liabilities	972	5,837
Operating lease liabilities	(6,576)	(5,199)
Net cash (used for)/provided by operating activities	(13,555)	8,343
Cash flows from investing activities:
Purchases of property and equipment	(12,274)	(10,878)
Investment in equity affiliate	(700)	0
Purchase of investments	(23,830)	(47,683)
Proceeds from redemption of investments	72,844	21,361
Net cash provided by/(used for) investing activities	36,040	(37,200)
Cash flows from financing activities:
Principal payments of finance lease liabilities	(67)	(137)
Proceeds from borrowings	110,000	46,000
Repayments of borrowings	(10,201)	(10,572)
Payment of debt issuance costs	0	(97)
Acquisition of treasury stock	(13,995)	(15,408)
Proceeds from exercise of stock options	921	22
Net cash provided by financing activities	86,658	19,808
Effect of exchange rate changes on cash, cash equivalents and restricted cash	(2,653)	(455)
Net increase/(decrease) in cash, cash equivalents and restricted cash	106,490	(9,504)
Cash, cash equivalents and restricted cash at the beginning of the period	127,044	104,131
Cash, cash equivalents and restricted cash at the end of the period	$ 233,534	$ 94,627