CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021
Cash flows from operating activities:
Net income	$ 108,323	$ 223,717
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization expense	47,250	38,261
Operating lease right-of-use assets amortization expense	26,037	31,496
Bad debt expense	11,748	2,828
Deferred taxes	(29,405)	1,176
Stock-based compensation expense	35,005	48,451
Unrealized loss on derivative	32,013	0
Impairment charges	21,002	0
Other	75,433	(5,190)
Changes in assets and liabilities:
Trade receivables and contract assets	(183,143)	(168,038)
Prepaid and other assets	(3,350)	(7,795)
Accounts payable	725	(3,948)
Accrued expenses and other liabilities	(62,153)	(6,772)
Operating lease liabilities	(29,015)	(32,276)
Income taxes payable	(24,803)	(40,247)
Net cash provided by operating activities	25,667	81,663
Cash flows from investing activities:
Purchases of property and equipment	(41,426)	(33,773)
Purchases of short-term investments	(60,000)	0
Proceeds from short-term investments	0	60,000
Acquisition of business, net of cash acquired	(10,621)	(121,252)
Purchases of non-marketable securities	0	(2,544)
Other investing activities, net	(11,041)	179
Net cash used in investing activities	(123,088)	(97,390)
Cash flows from financing activities:
Proceeds from issuance of stock under the employee incentive programs	22,165	15,610
Payments of withholding taxes related to net share settlements of restricted stock units	(20,796)	(33,696)
Proceeds from debt	3,227	0
Repayment of debt	(10,756)	0
Payment of contingent consideration for previously acquired business	(207)	(1,047)
Purchase of noncontrolling interest	(2,146)	0
Other financing activities, net	(2,121)	137
Net cash used in financing activities	(10,634)	(18,996)
Effect of exchange rate changes on cash, cash equivalents and restricted cash	(45,661)	(3,761)
Net decrease in cash, cash equivalents and restricted cash	(153,716)	(38,484)
Cash, cash equivalents and restricted cash, beginning of period	1,449,347	1,323,533
Cash, cash equivalents and restricted cash, end of period	$ 1,295,631	$ 1,285,049