Shareholders' Equity Amounts Reclassified from Accumulated Other Comprehensive Loss (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013		Apr. 01, 2012
Tax (expense) benefit	$ 0		$ 0
Net of tax	1,334		977
Accumulated Defined Benefit Plans Adjustment [Member]
Transition asset	(26)	[1]	(33)	[1]
Actuarial loss	1,399	[1]	1,051	[1]
Prior service cost	(39)	[1]	(41)	[1]
Total before tax	1,334		977
Tax (expense) benefit	0	[2]	0	[2]
Net of tax	$ 1,334		$ 977

[1] (a) These components of accumulated other comprehensive loss are included in the computation of net periodic pension cost (see Note 9, Pension and Other Postretirement Benefits, for additional details), which is included in selling, general and administrative expense in our condensed consolidated statements of operations.

[2] In the first quarter of 2012 and 2013, we have a full valuation allowance recorded against our deferred tax assets. Accordingly, we do not incur any tax expense or realize any tax benefits related to our pension plan activity.