Business Acquisitions (Allocation of Aggregate Purchase Price) (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021	Sep. 30, 2021	Jun. 04, 2021
Business Acquisition [Line Items]
Goodwill	$ 1,579,957	$ 1,531,455
Fiscal 2022 Acquisitions
Business Acquisition [Line Items]
Accounts receivable	7,433
Prepaid expenses and other current assets	4,915
Property and equipment	369
Operating lease right-of-use assets, noncurrent	546
Goodwill	93,827
Other long-term assets	11
Accounts payables and accrued expenses	(4,656)
Deferred revenue	(21,332)
Deferred tax liability	(10,436)
Other long-term liabilities	(516)
Total	121,704
Fiscal 2022 Acquisitions | Trade names
Business Acquisition [Line Items]
Finite-lived intangible assets	12,838
Fiscal 2022 Acquisitions | Customer relationship
Business Acquisition [Line Items]
Finite-lived intangible assets	20,540
Fiscal 2022 Acquisitions | Other intangibles
Business Acquisition [Line Items]
Finite-lived intangible assets	$ 18,165
Fiscal 2021 Acquisitions
Business Acquisition [Line Items]
Accounts receivable			$ 4,577
Prepaid expenses and other current assets			2,585
Property and equipment			1,838
Operating lease right-of-use assets, noncurrent			5,888
Goodwill			84,019
Other long-term assets			62
Deferred tax asset			231
Accounts payables and accrued expenses			(2,891)
Deferred revenue		$ (9,500)	(7,806)
Operating lease liabilities, current			(7,191)
Other current liabilities			(14)
Deferred tax liability			(4,122)
Other long-term liabilities			(1,726)
Total			134,342
Fiscal 2021 Acquisitions | Trade names
Business Acquisition [Line Items]
Finite-lived intangible assets			11,118
Fiscal 2021 Acquisitions | Customer relationship
Business Acquisition [Line Items]
Finite-lived intangible assets			13,396
Fiscal 2021 Acquisitions | Other intangibles
Business Acquisition [Line Items]
Finite-lived intangible assets			$ 34,378
SEOmoz Acquisition
Business Acquisition [Line Items]
Accounts receivable				$ 3,278
Prepaid expenses and other current assets				2,512
Property and equipment				1,838
Operating lease right-of-use assets, noncurrent				5,888
Goodwill				41,192
Other long-term assets				62
Accounts payables and accrued expenses				(2,421)
Deferred revenue				(7,048)
Operating lease liabilities, current				(7,191)
Other current liabilities				(14)
Deferred tax liability				(4,122)
Other long-term liabilities				(785)
Total				66,996
SEOmoz Acquisition | Trade names
Business Acquisition [Line Items]
Finite-lived intangible assets				7,200
SEOmoz Acquisition | Customer relationship
Business Acquisition [Line Items]
Finite-lived intangible assets				5,000
SEOmoz Acquisition | Other intangibles
Business Acquisition [Line Items]
Finite-lived intangible assets				$ 21,607