Acquisitions - Schedule of Acquisition Price Allocation (Detail) - USD ($) $ in Thousands	Jun. 30, 2018	May 25, 2018	Dec. 31, 2017
Intangible assets, net acquired:
Goodwill	$ 949,258		$ 730,464
Gram Games [Member]
Business Acquisition [Line Items]
Cash acquired		$ 8,474
Accounts receivable, net acquired	$ 10,700	10,747
Prepaid expenses acquired		279
Other current assets acquired		937
Intangible assets, net acquired:
Goodwill		223,833
Property and equipment, net acquired		898
Other non-current assets acquired		329
Total assets acquired		328,997
Accounts payable assumed		(8,874)
Income tax payable assumed		(502)
Other current liabilities assumed		(5,164)
Deferred tax liabilities, net assumed		(15,408)
Total liabilities assumed		(29,948)
Total purchase price consideration		299,049
Non-current contingent consideration obligation		(43,500)
Total cash consideration		255,549
Gram Games [Member] | Developed Technology, Useful Life of 5 Years [Member]
Intangible assets, net acquired:
Intangible assets, net acquired		43,000
Gram Games [Member] | Developed Technology, Useful Life of 3 Years [Member]
Intangible assets, net acquired:
Intangible assets, net acquired		26,000
Gram Games [Member] | Trade Names, Useful Life of 7 Years [Member]
Intangible assets, net acquired:
Intangible assets, net acquired		14,000
Gram Games [Member] | Trade Names, Useful Life of 3 Years [Member]
Intangible assets, net acquired:
Intangible assets, net acquired		$ 500