Accumulated Other Comprehensive Income (Loss) Accumulated Other Comprehensive Income (Loss) (Parentheticals) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 29, 2018	Dec. 30, 2017	Dec. 31, 2016
Accumulated Other Comprehensive Income (Loss) [Line Items]
Unrealized gain (loss) on interest rate swaps, tax	$ 0	$ 68	$ (100)
Reclassification of loss into earnings from interest rate swaps, tax	0	475	491
Unrecognized net actuarial gain on postretirment benefit plans, tax	0	4	(1)
Reclassification of net actuarial gain into earnings from postretirement benefit plans, tax	0	(11)	(13)
Reclassification of prior service credits into earnings from postretirement benefit plans, tax	0	(1)	(2)
Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Unrealized gain (loss) on interest rate swaps, tax	0	68	(100)
Reclassification of loss into earnings from interest rate swaps, tax	0	475	491
Amortization of unrealized loss on dedesignated interest rate swaps, tax	0	0	0
Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Unrecognized net actuarial gain on postretirment benefit plans, tax	0	4	(1)
Reclassification of net actuarial gain into earnings from postretirement benefit plans, tax	0	(11)	(13)
Reclassification of prior service credits into earnings from postretirement benefit plans, tax	$ 0	$ (1)	$ (2)