CONSOLIDATED AND COMBINED FINANCIAL STATEMENT DETAILS (Tables)

12 Months Ended

Dec. 31, 2017

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Schedule of Other Current Assets

	December 31,
	2017		2016
	(In thousands)
Other current assets:
Prepaid expenses	$	10,937	$	6,456
Other	1,835		2,283
Other current assets	$	12,772	$	8,739

Schedule of Property and Equipment, Net

Property and equipment, including significant improvements, are recorded at cost. Repairs and maintenance costs are expensed as incurred. Depreciation is computed using the straight-line method over the estimated useful lives of the assets, or, in the case of leasehold improvements, the lease term, if shorter.

Asset Category	Estimated Useful Lives
Computer equipment and capitalized software	2 to 3 Years
Furniture and other equipment	5 to 7 Years
Buildings and leasehold improvements	5 to 25 Years

	December 31,
	2017			2016
	(In thousands)
Property and equipment, net of accumulated depreciation and amortization:
Computer equipment and capitalized software	$	41,853		$	27,309
Buildings and leasehold improvements	13,984			6,075
Furniture and other equipment	6,222			3,140
Projects in progress	12,801			5,198
Land	2,800			—
	77,660			41,722
Accumulated depreciation and amortization	(24,368		)	(18,077		)
Property and equipment, net of accumulated depreciation and amortization	$	53,292		$	23,645

Schedule of Accrued Expenses and Other Current Liabilities

	December 31,
	2017		2016
	(In thousands)
Accrued expenses and other current liabilities:
Accrued employee compensation and benefits	$	30,354	$	14,379
Accrued advertising expense	17,243		8,209
Other	27,574		11,850
Accrued expenses and other current liabilities	$	75,171	$	34,438

Schedule of Other Income (Expense), Net

	Years Ended December 31,
	2017		2016			2015
	(In thousands)
Other income (expense), net	$	1,974	$	(699	)	$	(398	)