Consolidated Statements of Comprehensive Income (Loss) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 28, 2013	Dec. 29, 2012	Dec. 31, 2011
Statement Of Income And Comprehensive Income [Abstract]
Net income (loss)	$ (33,418)	$ (12,243)	$ 15,719
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustments	3,270	1,689	(1,076)
Adjustments related to postretirement benefits, net of income taxes	1,604	122	1,267
Change in unrealized gain/loss on investments	(6)	(16)	(6)
Other comprehensive income, net of tax	4,868	1,795	185
Comprehensive income (loss)	$ (28,550)	$ (10,448)	$ 15,904