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ACQUISITIONS - Schedule of Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Thousands	May 31, 2018	Sep. 30, 2019	Dec. 31, 2018
Recognized amounts of identifiable assets acquired and liabilities assumed:
Goodwill		$ 265,974	$ 261,705
Weebly, Inc.
Consideration:
Cash	$ 132,432
Stock (2,418,271 shares of Class A common stock)	$ 140,107
Shares of Class A common stock (in shares)	2,418,271
Total consideration	$ 272,539
Recognized amounts of identifiable assets acquired and liabilities assumed:
Current assets (inclusive of cash acquired of $25,758)	46,978
Cash acquired	25,758
Total liabilities assumed (including deferred revenue of $22,800)	(37,509)
Deferred revenue	22,800
Total identifiable net assets acquired	79,330
Goodwill	193,209
Total	272,539
Weebly, Inc. \| Intangible customer assets
Recognized amounts of identifiable assets acquired and liabilities assumed:
Intangible assets	42,700
Weebly, Inc. \| Intangible technology assets
Recognized amounts of identifiable assets acquired and liabilities assumed:
Intangible assets	14,900
Weebly, Inc. \| Intangible trade name
Recognized amounts of identifiable assets acquired and liabilities assumed:
Intangible assets	11,300
Weebly, Inc. \| Intangible other assets
Recognized amounts of identifiable assets acquired and liabilities assumed:
Intangible assets	$ 961