Acquisitions - HWW (Details) - USD ($) $ in Thousands				12 Months Ended
	Oct. 01, 2014	Jul. 04, 2014	Dec. 27, 2013	Dec. 31, 2016	Dec. 31, 2015	Dec. 28, 2014
Business Acquisition [Line Items]
Cash			$ 2,816,000
Net cash				$ 0	$ 74,959	$ 279,833
Goodwill				$ 3,227,930	$ 3,228,224	$ 3,601,300
What's On India Media Private Limited
Business Acquisition [Line Items]
Cash		$ 23,403
Cash acquired		(2,203)
Net cash		21,000
Accounts receivable and other current assets		1,407
Property and equipment		163
Accounts payable and other current liabilities		(1,437)
Deferred income taxes		(4,393)
Total identifiable net assets		11,149
Goodwill		15,676
Total net assets acquired		$ 26,825
Definite-lived intangible assets useful life, years		10 years
HWW
Business Acquisition [Line Items]
Cash	$ 18,425
Cash acquired	(176)
Net cash	18,249
Accounts receivable and other current assets	780
Property and equipment	40
Accounts payable and other current liabilities	(147)
Deferred revenue	(267)
Deferred income taxes	(2,550)
Other liabilities	(45)
Total identifiable net assets	6,311
Goodwill	11,938
Total net assets acquired	$ 18,249
Definite-lived intangible assets useful life, years	8 years
Technologies | What's On India Media Private Limited
Business Acquisition [Line Items]
Intangible assets subject to amortization		$ 3,100
Definite-lived intangible assets useful life, years		7 years
Technologies | HWW
Business Acquisition [Line Items]
Intangible assets subject to amortization	$ 3,600
Definite-lived intangible assets useful life, years	7 years
Customer relationships | What's On India Media Private Limited
Business Acquisition [Line Items]
Intangible assets subject to amortization		$ 2,800
Definite-lived intangible assets useful life, years		7 years
Customer relationships | HWW
Business Acquisition [Line Items]
Intangible assets subject to amortization	$ 2,500
Definite-lived intangible assets useful life, years	12 years
Content database | What's On India Media Private Limited
Business Acquisition [Line Items]
Intangible assets subject to amortization		$ 7,700
Definite-lived intangible assets useful life, years		13 years
Content database | HWW
Business Acquisition [Line Items]
Intangible assets subject to amortization	$ 2,400
Definite-lived intangible assets useful life, years	5 years