Condensed Consolidated Statements Of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Operating Activities
Net income	$ 392,355	$ 474,700
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and other	159,283	188,443
Stock-based compensation expense	228,854	202,523
Deferred income tax benefit	(34,372)	(184,573)
Effects of exchange rate changes on monetary assets and liabilities denominated in foreign currencies	(9,225)	2,712
Other non-cash items	16,196	7,888
Total adjustments to reconcile net income to net cash provided by operating activities	360,736	216,993
Changes in operating assets and liabilities:
Accounts receivable	150,347	256,628
Inventories	(592)	443
Prepaid expenses and other current assets	(39,049)	(13,539)
Other assets	(67,139)	(50,068)
Income taxes, net	16,640	(42,119)
Accounts payable	17,973	(2,645)
Accrued expenses and other current liabilities	73,737	(48,485)
Deferred revenues	(103,487)	(219,000)
Other liabilities	14,252	4,111
Total changes in operating assets and liabilities	62,682	(114,674)
Net cash provided by operating activities	815,773	577,019
Investing Activities
Purchases of available-for-sale investments	(476,432)	(19,999)
Proceeds from sales of available-for-sale investments	0	938,031
Proceeds from maturities of available-for-sale investments	166,077	165,944
Purchases of property and equipment	(30,783)	(50,453)
Cash paid for licensing agreements, patents and technology	(5,581)	(2,405)
Other	923	919
Net cash (used in) provided by investing activities	(345,796)	1,032,037
Financing Activities
Proceeds from term loan credit agreement, net of issuance costs	998,846	0
Repayment of term loan credit agreement	(750,000)	0
Proceeds from 2030 Notes, net of issuance costs	738,107	0
Proceeds from credit facility	0	200,000
Repayment of credit facility	0	(200,000)
Repayment on convertible notes	0	(1,164,497)
Stock repurchases, net	(1,199,903)	(353,904)
Cash paid for tax withholding on vested stock awards	(104,848)	(74,794)
Cash paid for dividends	(129,108)	(137,224)
Net cash used in financing activities	(446,906)	(1,730,419)
Effect of exchange rate changes on cash and cash equivalents	(8)	(3,569)
Change in cash and cash equivalents	23,063	(124,932)
Cash and cash equivalents at beginning of period	545,761	618,766
Cash and cash equivalents at end of period	$ 568,824	$ 493,834