Convertible Senior Notes - Components of Convertible Senior Notes (Details) (USD $)	Mar. 28, 2015		Dec. 27, 2014		May 30, 2013
Debt Instrument [Line Items]
Unamortized discount	$ 31,049,000	[1]	$ 33,106,000	[1]
Unamortized issuance cost	(2,671,000)	[1]	(2,848,000)	[1]
1.75% Convertible Senior Notes Due June 1, 2018
Debt Instrument [Line Items]
Principal amount					150,000,000.0
Initial transaction amount and net carrying amount, APIC	43,300,000		43,341,000
Convertible Debt, Noncurrent	116,280,000		114,046,000
1.75% Convertible Senior Notes Due June 1, 2018 | Additional Paid-in Capital
Debt Instrument [Line Items]
Equity component	45,000,000		45,000,000
Debt issuance cost	1,700,000		(1,659,000)
1.75% Convertible Senior Notes Due June 1, 2018 | Long-term Debt
Debt Instrument [Line Items]
Principal amount	$ 150,000,000		$ 150,000,000

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