Revenue - Digital-only Subscription Revenue (Details) - USD ($) $ in Thousands	3 Months Ended
	Apr. 01, 2018	Mar. 26, 2017
Disaggregation of Revenue [Line Items]
Digital-only subscription revenue	$ 413,948	$ 398,804
News Products
Disaggregation of Revenue [Line Items]
Digital-only subscription revenue	90,577	72,861
Other Products
Disaggregation of Revenue [Line Items]
Digital-only subscription revenue	4,835	2,956
Total digital-only subscription revenues
Disaggregation of Revenue [Line Items]
Digital-only subscription revenue	$ 95,412	$ 75,817