Convertible Senior Notes - Components of Convertible Senior Notes (Details) (USD $)	Dec. 27, 2014		Dec. 28, 2013		May 30, 2013
Debt Instrument [Line Items]
Unamortized Discount	$ 30,257,000	[1]	$ 37,322,000	[1]
1.75% Convertible Senior Notes Due June 1, 2018 [Member]
Debt Instrument [Line Items]
Principal amount					150,000,000.0
Convertible Debt, Noncurrent	119,743,000		112,678,000
Debt Instrument Net Equity Component Carrying Amount	43,341,000		43,341,000
1.75% Convertible Senior Notes Due June 1, 2018 [Member] | Additional Paid-in Capital
Debt Instrument [Line Items]
Equity component	45,000,000		45,000,000
Debt issuance cost	(1,659,000)		(1,659,000)
1.75% Convertible Senior Notes Due June 1, 2018 [Member] | Long-term Debt [Member]
Debt Instrument [Line Items]
Principal amount	$ 150,000,000		$ 150,000,000

[1] Unamortized discount includes debt conversion discount and issuance costs, which will be amortized over the remaining life of the Notes, which is approximately 4 years.