Condensed Consolidated Statements Of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Operating Activities
Net income	$ 263,170	$ 336,262
Loss (income) from discontinued operations	42,704	(44,982)
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and other	149,813	166,381
Stock-based compensation expense	127,219	115,271
Excess tax benefit from stock-based compensation	0	(12,374)
Deferred income tax expense (benefit)	32,367	(23,912)
Effects of exchange rate changes on monetary assets and liabilities denominated in foreign currencies	(8,063)	(3,489)
Other non-cash items	9,608	6,385
Total adjustments to reconcile net income to net cash provided by operating activities	310,944	248,262
Changes in operating assets and liabilities, net of the effects of acquisitions:
Accounts receivable	216,139	190,685
Inventories	(3,350)	(5,354)
Prepaid expenses and other current assets	(15,836)	13,651
Other assets	(2,393)	(7,722)
Income taxes, net	(58,278)	70,753
Accounts payable	(17,039)	(19,288)
Accrued expenses and other current liabilities	(17,372)	(6,236)
Deferred revenues	(10,746)	(51,078)
Other liabilities	2,645	14,664
Total changes in operating assets and liabilities, net of the effects of acquisitions	93,770	200,075
Net cash provided by operating activities of continuing operations	710,588	739,617
Net cash (used in) provided by operating activities of discontinued operations	(56,070)	117,166
Net cash provided by operating activities	654,518	856,783
Investing Activities
Purchases of available-for-sale investments	(966,067)	(1,411,077)
Proceeds from sales of available-for-sale investments	678,533	1,156,168
Proceeds from maturities of available-for-sale investments	377,719	511,023
Purchases of property and equipment	(61,670)	(66,267)
Cash paid for acquisitions, net of cash acquired	(60,449)	(11,456)
Cash paid for licensing agreements and technology	(5,865)	(25,755)
Other	490	464
Net cash (used in) provided by investing activities of continuing operations	(37,309)	153,100
Net cash used for investing activities of discontinued operations	(3,891)	(39,395)
Net cash provided by (used in) investing activities	(41,200)	113,705
Financing Activities
Proceeds from issuance of common stock under stock-based compensation plans	2,094	39,438
Proceeds from credit facility	165,000	0
Repayment of credit facility	(125,000)	0
Repayment of acquired debt	(4,000)	0
Excess tax benefit from stock-based compensation	0	12,374
Stock repurchases, net	(574,957)	(28,689)
Cash paid for tax withholding on vested stock awards	(71,179)	(55,402)
Transfer of cash to GoTo Business resulting from the separation	(28,523)	0
Net cash used in financing activities	(636,565)	(32,279)
Effect of exchange rate changes on cash and cash equivalents	7,160	1,956
Change in cash and cash equivalents	(16,087)	940,165
Cash and cash equivalents at beginning of period, including cash of discontinued operations of $120,861 and $57,762, respectively	956,956	368,518
Cash and cash equivalents at end of period	940,869	1,308,683
Less cash of discontinued operations	0	(79,020)
Cash and cash equivalents at end of period	$ 940,869	$ 1,229,663