Revenue - Advertising Revenues (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 29, 2019	Sep. 30, 2018	Sep. 29, 2019	Sep. 30, 2018
Disaggregation of Revenue [Line Items]
Advertising revenue	$ 428,501	$ 417,346	$ 1,303,821	$ 1,245,854
Display
Disaggregation of Revenue [Line Items]
Advertising revenue	87,904	100,975	291,050	312,723
Other
Disaggregation of Revenue [Line Items]
Advertising revenue	25,627	20,702	68,330	53,802
Total advertising
Disaggregation of Revenue [Line Items]
Advertising revenue	113,531	121,677	359,380	366,525
Print | Display
Disaggregation of Revenue [Line Items]
Advertising revenue	51,702	57,245	169,903	188,853
Print | Other
Disaggregation of Revenue [Line Items]
Advertising revenue	7,176	6,676	21,255	22,182
Print | Total advertising
Disaggregation of Revenue [Line Items]
Advertising revenue	58,878	63,921	191,158	211,035
Digital | Display
Disaggregation of Revenue [Line Items]
Advertising revenue	36,202	43,730	121,147	123,870
Digital | Other
Disaggregation of Revenue [Line Items]
Advertising revenue	18,451	14,026	47,075	31,620
Digital | Total advertising
Disaggregation of Revenue [Line Items]
Advertising revenue	$ 54,653	$ 57,756	$ 168,222	$ 155,490