Revenue - Digital-only Subscription Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 01, 2018	Jun. 25, 2017	Jul. 01, 2018	Jun. 25, 2017
Disaggregation of Revenue [Line Items]
Digital-only subscription revenue	$ 414,560	$ 407,074	$ 828,508	$ 805,878
News Products
Disaggregation of Revenue [Line Items]
Digital-only subscription revenue	93,549	79,300	184,125	152,161
Other Products
Disaggregation of Revenue [Line Items]
Digital-only subscription revenue	5,194	3,243	10,030	6,199
Total digital-only subscription revenues
Disaggregation of Revenue [Line Items]
Digital-only subscription revenue	$ 98,743	$ 82,543	$ 194,155	$ 158,360