Business Acquisitions (Details) - USD ($) $ in Thousands					1 Months Ended	12 Months Ended
	Nov. 10, 2019	Nov. 01, 2019	Nov. 27, 2017	Apr. 06, 2017	Jan. 31, 2019	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Business Acquisition [Line Items]
Acquisition related costs						$ 1,900	$ 1,000	$ 5,500
Allocation of the purchase consideration:
Goodwill						1,600,265	$ 1,487,404	$ 1,498,688
ChameleonX
Business Acquisition [Line Items]
Cash transferred	$ 11,900
Allocation of the purchase consideration:
Identifiable intangible assets	6,100
Goodwill	7,100
Goodwill, expected tax deductible amount	$ 7,100
Weighted average useful life	7 years 1 month 6 days
Exceda
Business Acquisition [Line Items]
Cash transferred		$ 32,700
Allocation of the purchase consideration:
Identifiable intangible assets		16,500
Goodwill		14,700
Goodwill, expected tax deductible amount		14,700
Indemnification asset		$ 20,000
Weighted average useful life		8 years 1 month 6 days
Janrain, Inc.
Business Acquisition [Line Items]
Cash transferred					$ 123,600
Total purchase consideration					123,632
Allocation of the purchase consideration:
Cash					2,223
Accounts receivable					7,318
Prepaid expenses and other current assets					838
Identifiable intangible assets					26,930
Goodwill					92,188
Deferred tax assets					12,622	$ 7,500
Other assets					87
Total assets acquired					142,206
Accounts payable					(1,642)
Accrued liabilities					(2,596)
Deferred revenue					(14,336)
Total liabilities assumed					(18,574)
Net assets acquired					123,632
Goodwill, expected tax deductible amount					46,800
Gross carrying amount of intangible assets					$ 26,930
Weighted average useful life					11 years 9 months 18 days
Janrain, Inc. | Completed technologies
Allocation of the purchase consideration:
Gross carrying amount of intangible assets					$ 9,000
Weighted average useful life					7 years 10 months 24 days
Janrain, Inc. | Customer-related intangible assets
Allocation of the purchase consideration:
Gross carrying amount of intangible assets					$ 17,700
Weighted average useful life					13 years 10 months 24 days
Janrain, Inc. | Trademarks
Allocation of the purchase consideration:
Gross carrying amount of intangible assets					$ 200
Weighted average useful life					1 year 10 months 24 days
Janrain, Inc. | Non-compete agreements
Allocation of the purchase consideration:
Gross carrying amount of intangible assets					$ 30
Weighted average useful life					1 year 10 months 24 days
Nominum, Inc.
Business Acquisition [Line Items]
Cash transferred			$ 180,300
Total purchase consideration			180,327
Allocation of the purchase consideration:
Cash			8,455
Accounts receivable			9,845
Prepaid expenses and other current assets			1,082
Identifiable intangible assets			33,200
Goodwill			129,876
Fixed assets			1,570
Deferred tax assets			16,080
Other assets			19
Total assets acquired			200,127
Accounts payable			(1,501)
Accrued liabilities			(3,471)
Deferred revenue			(14,828)
Total liabilities assumed			(19,800)
Net assets acquired			180,327
Goodwill, expected tax deductible amount			54,100
Gross carrying amount of intangible assets			$ 33,200
Weighted average useful life			5 years 4 months 24 days
Nominum, Inc. | Completed technologies
Allocation of the purchase consideration:
Gross carrying amount of intangible assets			$ 7,200
Weighted average useful life			2 years 2 months 12 days
Nominum, Inc. | Customer-related intangible assets
Allocation of the purchase consideration:
Gross carrying amount of intangible assets			$ 24,700
Weighted average useful life			6 years 6 months
Nominum, Inc. | Trademarks
Allocation of the purchase consideration:
Gross carrying amount of intangible assets			$ 1,100
Weighted average useful life			3 years 8 months 12 days
Nominum, Inc. | Non-compete agreements
Allocation of the purchase consideration:
Gross carrying amount of intangible assets			$ 200
Weighted average useful life			1 year 6 months
Soasta, Inc.
Business Acquisition [Line Items]
Cash transferred				$ 199,300
Total purchase consideration				199,280
Allocation of the purchase consideration:
Cash				1,935
Accounts receivable				4,109
Prepaid expenses and other current assets				4,384
Identifiable intangible assets				49,900
Goodwill				122,794
Deferred tax assets				31,206
Total assets acquired				214,328
Accounts payable				(1,119)
Accrued liabilities				(4,366)
Deferred revenue				(9,563)
Total liabilities assumed				(15,048)
Net assets acquired				199,280
Goodwill, expected tax deductible amount				36,400
Gross carrying amount of intangible assets				$ 49,900
Weighted average useful life				4 years 4 months 24 days
Soasta, Inc. | Completed technologies
Allocation of the purchase consideration:
Gross carrying amount of intangible assets				$ 18,800
Weighted average useful life				4 years 1 month 6 days
Soasta, Inc. | Customer-related intangible assets
Allocation of the purchase consideration:
Gross carrying amount of intangible assets				$ 28,200
Weighted average useful life				4 years 7 months 6 days
Soasta, Inc. | Trademarks
Allocation of the purchase consideration:
Gross carrying amount of intangible assets				$ 2,400
Weighted average useful life				4 years 10 months 24 days
Soasta, Inc. | Non-compete agreements
Allocation of the purchase consideration:
Gross carrying amount of intangible assets				$ 500
Weighted average useful life				1 year 10 months 24 days