Accumulated Other Comprehensive Income (Loss) (Accumulated Other Comprehensive Income (Loss)) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 28, 2019	Sep. 29, 2018	Sep. 28, 2019	Sep. 29, 2018
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss) - total			$ (108)
Unrealized gain on interest rate swaps, net	$ (159)	$ 261	(1,264)	$ 1,389
Reclassification of loss into earnings from interest rate swaps, net	125	150	263	555
Reclassification of net actuarial gain into earnings from postretirement benefit plans, net	(7)	(7)	(19)	(22)
Reclassification of prior service credits into earnings from postretirement benefit plans, net	(1)	$ (1)	(3)	$ (3)
Accumulated other comprehensive income (loss) - total	(1,131)		(1,131)
Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss) - total			(383)
Unrealized gain on interest rate swaps, net			(1,264)
Reclassification of loss into earnings from interest rate swaps, net			263
Accumulated other comprehensive income (loss) - total	(1,384)		(1,384)
Accumulated Defined Benefit Plans Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss) - total			275
Reclassification of net actuarial gain into earnings from postretirement benefit plans, net			(19)
Reclassification of prior service credits into earnings from postretirement benefit plans, net			(3)
Accumulated other comprehensive income (loss) - total	$ 253		$ 253