Condensed Consolidated Statements Of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Operating Activities
Net income	$ 144,259	$ 27,621
Loss from discontinued operations	0	42,704
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and other	51,876	49,300
Stock-based compensation expense	35,723	34,808
Deferred income tax expense	8,160	67,497
Effects of exchange rate changes on monetary assets and liabilities denominated in foreign currencies	(1,906)	(5,390)
Other non-cash items	3,302	2,204
Total adjustments to reconcile net income to net cash provided by operating activities	97,155	148,419
Changes in operating assets and liabilities, net of the effects of acquisitions:
Accounts receivable	285,104	197,408
Inventories	34	(2,811)
Prepaid expenses and other current assets	(13,494)	(22,736)
Other assets	9,071	(8,845)
Income taxes, net	(35,996)	(30,223)
Accounts payable	1,828	(8,222)
Accrued expenses and other current liabilities	(52,735)	(27,959)
Deferred revenues	(79,890)	(26,064)
Other liabilities	2,519	2,241
Total changes in operating assets and liabilities, net of the effects of acquisitions	116,441	72,789
Net cash provided by operating activities of continuing operations	357,855	291,533
Net cash used in operating activities of discontinued operations	0	(42,249)
Net cash provided by operating activities	357,855	249,284
Investing Activities
Purchases of available-for-sale investments	(125,687)	(272,060)
Proceeds from sales of available-for-sale investments	358,465	458,020
Proceeds from maturities of available-for-sale investments	95,341	63,516
Purchases of property and equipment	(15,997)	(19,746)
Cash paid for acquisitions, net of cash acquired	(66,330)	(60,449)
Cash paid for licensing agreements and technology	(535)	(1,934)
Other	3,257	1,285
Net cash provided by investing activities of continuing operations	248,514	168,632
Net cash used in investing activities of discontinued operations	0	(3,891)
Net cash provided by investing activities	248,514	164,741
Financing Activities
Proceeds from issuance of common stock under stock-based compensation plans	70	902
Proceeds from credit facility	0	100,000
Repayment of acquired debt	(5,674)	(4,000)
Stock repurchases, net	(600,000)	(500,000)
Accelerated stock repurchase program	(150,000)	0
Cash paid for tax withholding on vested stock awards	(13,602)	(34,868)
Transfer of cash to GoTo Business resulting from the separation	0	(28,523)
Net cash used in financing activities	(769,206)	(466,489)
Effect of exchange rate changes on cash and cash equivalents	2,404	3,485
Change in cash and cash equivalents	(160,433)	(48,979)
Cash and cash equivalents at beginning of period, including cash of discontinued operations of $0 and $120,861, respectively	1,115,130	956,956
Cash and cash equivalents at end of period	$ 954,697	$ 907,977