Goodwill and other intangible assets (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 30, 2012
Customer Relationships [Member]
Goodwill, indefinite-lived intangible assets, and amortizable intangible assets
Gross	$ 312,422	$ 313,567
Accumulated Amortization	203,144	197,300
Other [Member]
Goodwill, indefinite-lived intangible assets, and amortizable intangible assets
Gross	56,680	56,965
Accumulated Amortization	25,244	23,931
Mastheads and trade names [Member]
Goodwill, indefinite-lived intangible assets, and amortizable intangible assets
Gross	94,733	95,308
Accumulated Amortization	0	0
Television station FCC licenses [Member]
Goodwill, indefinite-lived intangible assets, and amortizable intangible assets
Gross	255,304	255,304
Accumulated Amortization	0	0
Goodwill [Member]
Goodwill, indefinite-lived intangible assets, and amortizable intangible assets
Gross	2,841,171	2,846,869
Accumulated Amortization	$ 0	$ 0