Accumulated Other Comprehensive Loss (Details 1) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Apr. 01, 2012
Subtotal pre-tax	$ 1,164	$ 932
Income tax expense	(457)	(367)
Total after tax effect	707	565
Net Pension Activity [Member]
Subtotal pre-tax	842	698
Income tax expense	(330)	(275)
Total after tax effect	512	423
Net Postretirement Benefits Activity [Member]
Subtotal pre-tax	322	234
Income tax expense	(127)	(92)
Total after tax effect	195	142
Cost of sales [Member]
Subtotal pre-tax	115	105
Cost of sales [Member] | Net Pension Activity [Member]
Subtotal pre-tax	76	77
Cost of sales [Member] | Net Postretirement Benefits Activity [Member]
Subtotal pre-tax	39	28
S,D&A expenses [Member]
Subtotal pre-tax	1,049	827
S,D&A expenses [Member] | Net Pension Activity [Member]
Subtotal pre-tax	766	621
S,D&A expenses [Member] | Net Postretirement Benefits Activity [Member]
Subtotal pre-tax	$ 283	$ 206