Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 26, 2020	Sep. 28, 2019	Sep. 26, 2020	Sep. 28, 2019
Statement of Comprehensive Income [Abstract]
Net Income	$ 6,501	$ 8,303	$ 19,521	$ 23,590
Other Comprehensive Income, Net of Tax:
Amortization of actuarial loss and prior service costs, net of tax of $59 and $51 for the three months ended September 26, 2020 and September 28, 2019, respectively, and $177 and $154 for the nine months ended September 26, 2020 and September 28, 2019, respectively	189	170	567	510
Change in unrealized gains and losses on cash flow hedges, net of tax of zero and $29 for the three months ended September 26, 2020 and September 28, 2019, respectively, and $57 and $2 for the nine months ended September 26, 2020 and September 28, 2019, respectively	0	91	162	0
Other Comprehensive Income, Net of Tax	189	261	729	510
Comprehensive Income	$ 6,690	$ 8,564	$ 20,250	$ 24,100