Consolidated Statements of Comprehensive Income (USD $) In Thousands, unless otherwise specified	3 Months Ended								6 Months Ended		9 Months Ended		12 Months Ended
	Dec. 31, 2014	Sep. 27, 2014	Jun. 28, 2014	Mar. 29, 2014	Dec. 31, 2013	Sep. 28, 2013	Jun. 29, 2013	Mar. 30, 2013	Jun. 28, 2014	Jun. 29, 2013	Sep. 27, 2014	Sep. 28, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Statement of Comprehensive Income [Abstract]
Net Income	$ 5,156	$ 2,933	$ 6,619	$ 5,159	$ (5,244)	$ 6,985	$ 5,666	$ 3,971	$ 11,778	$ 9,637	$ 14,711	$ 16,622	$ 19,867	$ 11,378	$ 17,623
Pension Adjustments
Amortization of actuarial loss included in net income, net of tax benefit of $156, $408 and $427 for 2014, 2013 and 2012, respectively		(66)	(57)	(69)		(172)	(172)	(172)	(126)	(344)	(192)	(516)	263	685	720
Actuarial gain (loss) arising during the period, net of tax expense (benefit) of $(1,810), $1,737 and $(300) for 2014, 2013 and 2012, respectively													(3,052)	2,921	(863)
Other Comprehensive (Loss) Income		(66)	(57)	(69)		(172)	(172)	(172)	(126)	(344)	(192)	(516)	(2,789)	3,606	(143)
Comprehensive Income		$ 2,867	$ 6,562	$ 5,090		$ 6,813	$ 5,494	$ 3,799	$ 11,652	$ 9,293	$ 14,519	$ 16,106	$ 17,078	$ 14,984	$ 17,480