Investments - Cost Method Investments (Details) (USD $)	12 Months Ended			0 Months Ended	1 Months Ended		3 Months Ended		1 Months Ended
	Dec. 28, 2014	Dec. 29, 2013	Dec. 30, 2012	Feb. 03, 2012	May 31, 2012 Unit	Feb. 29, 2012 Unit	Jun. 29, 2014	Mar. 31, 2013	Oct. 31, 2012
Schedule of Cost-method Investments [Line Items]
Gain on sale of investments			$ 220,275,000
Proceeds from investments – net of purchases	7,331,000	12,004,000	250,918,000
Impairment of assets	0	0	5,500,000
Fenway Sports Group [Member] | Cost-method Investments [Member]
Schedule of Cost-method Investments [Line Items]
Gain on sale of investments							37,800,000	17,800,000
Units sold in Fenway Sports Group					210	100
Proceeds from investments – net of purchases				30,000,000	63,000,000
Indeed.com [Member] | Cost-method Investments [Member]
Schedule of Cost-method Investments [Line Items]
Gain on sale of investments									164,600,000
Proceeds from Sale of Cost Method Investments									167,000,000
Ongo Inc. [Member] | Cost-method Investments [Member]
Schedule of Cost-method Investments [Line Items]
Impairment of assets			$ 5,500,000