Revenue - Advertising Revenues (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 29, 2020	Mar. 31, 2019
Disaggregation of Revenue [Line Items]
Advertising revenue	$ 443,636	$ 439,062
Display
Disaggregation of Revenue [Line Items]
Advertising revenue	88,053	104,454
Other
Disaggregation of Revenue [Line Items]
Advertising revenue	18,084	20,634
Total advertising
Disaggregation of Revenue [Line Items]
Advertising revenue	106,137	125,088
Print | Display
Disaggregation of Revenue [Line Items]
Advertising revenue	48,159	62,342
Print | Other
Disaggregation of Revenue [Line Items]
Advertising revenue	6,820	7,203
Print | Total advertising
Disaggregation of Revenue [Line Items]
Advertising revenue	54,979	69,545
Digital
Disaggregation of Revenue [Line Items]
Advertising revenue	130,010	109,859
Digital | Display
Disaggregation of Revenue [Line Items]
Advertising revenue	39,894	42,112
Digital | Other
Disaggregation of Revenue [Line Items]
Advertising revenue	11,264	13,431
Digital | Total advertising
Disaggregation of Revenue [Line Items]
Advertising revenue	$ 51,158	$ 55,543