Condensed Consolidated Statements Of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Operating Activities
Net income	$ 152,814	$ 294,128
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and other	158,344	106,593
Stock-based compensation expense	168,793	143,685
Deferred income tax expense (benefit)	8,202	(20,952)
Effects of exchange rate changes on monetary assets and liabilities denominated in foreign currencies	7,944	(166)
Other non-cash items	(18,925)	19,920
Total adjustments to reconcile net income to net cash provided by operating activities	324,358	249,080
Changes in operating assets and liabilities, net of the effects of acquisitions:
Accounts receivable	207,883	95,329
Inventories	(2,006)	(1,894)
Prepaid expenses and other current assets	(22,928)	2,478
Other assets	(44,911)	(39,485)
Income taxes, net	(70,990)	25,621
Accounts payable	44,459	37,864
Accrued expenses and other current liabilities	(188,413)	37,995
Deferred revenues	(43,869)	(8,161)
Other liabilities	243	10,461
Total changes in operating assets and liabilities, net of the effects of acquisitions	(120,532)	160,208
Net cash provided by operating activities	356,640	703,416
Investing Activities
Purchases of available-for-sale investments	(12,151)	(305,224)
Proceeds from maturities of available-for-sale investments	119,771	39,154
Purchases of property and equipment	(44,876)	(21,078)
Cash paid for acquisitions, net of cash acquired	(2,022,304)	0
Cash paid for licensing agreements, patents and technology	(4,417)	(3,210)
Other	6,479	707
Net cash used in investing activities	(1,957,498)	(289,651)
Financing Activities
Proceeds from issuance of common stock under stock-based compensation plan	20	0
Proceeds from term loan credit agreement, net of issuance costs	997,947	998,846
Repayment of term loan credit agreement	0	(750,000)
Proceeds from senior notes, net of issuance costs	741,393	738,107
Repayment of acquired debt	(190,000)	0
Stock repurchases, net	0	(999,903)
Accelerated stock repurchase program	0	(200,000)
Cash paid for tax withholding on vested stock awards	(101,718)	(101,156)
Cash paid for dividends	(91,481)	(86,062)
Other	(5,438)	0
Net cash provided by (used in) financing activities	1,350,723	(400,168)
Effect of exchange rate changes on cash and cash equivalents	(1,648)	(4,286)
Change in cash and cash equivalents	(251,783)	9,311
Cash and cash equivalents at beginning of period	752,895	545,761
Cash and cash equivalents at end of period	$ 501,112	$ 555,072