Revenue - Digital-only Subscription Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 24, 2017	Sep. 30, 2018	Sep. 24, 2017
Disaggregation of Revenue [Line Items]
Total revenues	$ 417,346	$ 385,635	$ 1,245,854	$ 1,191,513
News Products
Disaggregation of Revenue [Line Items]
Total revenues	95,568	82,073	279,693	234,234
Other Products
Disaggregation of Revenue [Line Items]
Total revenues	5,639	3,610	15,669	9,810
Total digital-only subscription revenues
Disaggregation of Revenue [Line Items]
Total revenues	$ 101,207	$ 85,683	$ 295,362	$ 244,044