Consolidated Statements Of Comprehensive Income (Loss) (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 27, 2016	Mar. 29, 2015
Statement of Comprehensive Income [Abstract]
Net loss	$ (32,521)	$ (2,559)
Other comprehensive income (loss), net of tax:
Pension liability adjustments, net of tax benefit of $133 and $3	(21)	4,431
Other postretirement benefit adjustments, net of tax expense of $0 and $0	28	0
Change in realized and unrealized gains on derivative hedges, net of tax expense of $0 and $0	(311)	0
Foreign currency translation adjustment	2,192	(14,899)
Net other comprehensive income (loss)	1,888	(10,468)
Comprehensive loss	$ (30,633)	$ (13,027)