Other Comprehensive Income (Loss) - Reclassification out of Accumulated Other Comprehensive Income (Details) - Reclassification out of Accumulated Other Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 29, 2018	Dec. 30, 2017	Dec. 31, 2016
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Total	$ 529	$ 312	$ 270
Amortization of prior service
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Total	291	337	306
Settlement loss/curtailment (gain)
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Total	$ 238	$ (25)	$ (36)