Equity Method Investment (Details) $ in Thousands		12 Months Ended
	Oct. 31, 2009 USD ($) Royality_Installment_Payments	Dec. 31, 2017 USD ($)	Dec. 25, 2016 USD ($)	Dec. 27, 2015 USD ($)	Sep. 23, 2014	Dec. 29, 2013 USD ($)
Schedule of Equity Method Investments [Line Items]
Acquired interest in joint venture, Discovery Family Channel	50.00%				40.00%
Payment for purchase of interest in joint venture	$ 300,000
Percentage of fair market value of equity method investment				80.00%
Minimum royalty guarantee	$ 125,000
Number of annual installments for minimum royalty guarantee | Royality_Installment_Payments	5
Amount of annual installment for minimum royalty guarantee	$ 25,000					$ 25,000
Discovery Communications, Inc. [Member]
Schedule of Equity Method Investments [Line Items]
Joint Venture - Ownership Interest					60.00%
Payments made to Discovery under tax sharing agreement		$ 6,785	$ 6,520	$ 4,971
Net (gains) losses related to change in value of joint venture option agreement		(4,790)	410	3,020
Discovery Communications, Inc. [Member] | Other Liabilities [Member]
Schedule of Equity Method Investments [Line Items]
Option Agreement		23,980	28,770
Liability associated with investment in joint venture, including imputed interest		$ 30,043	52,473
Discovery Family Channel [Member]
Schedule of Equity Method Investments [Line Items]
Acquired interest in joint venture, Discovery Family Channel		40.00%
Prepaid Royalties		$ 55,072	66,017
Interest in joint venture		237,996	242,397
Discovery Family Channel [Member] | Other Assets [Member]
Schedule of Equity Method Investments [Line Items]
Prepaid Royalties		39,114	58,814
Discovery Family Channel [Member] | Prepaid Expenses and Other Current Assets [Member]
Schedule of Equity Method Investments [Line Items]
Prepaid Royalties		15,958	7,203
Discovery Family Channel [Member] | Other Expense [Member]
Schedule of Equity Method Investments [Line Items]
Earnings (loss) of joint venture		23,270	$ 23,764	$ 19,045
Discovery Family Channel [Member] | Discovery Communications, Inc. [Member]
Schedule of Equity Method Investments [Line Items]
Gain from reduction of remaining present value of expected future payments, tax cuts and jobs act		$ 19,911