Goodwill and Intangible Assets - Acquired and Amortization (Details) - USD ($) $ in Thousands	Sep. 28, 2019	Dec. 29, 2018
Acquired identifiable intangible assets
Acquired identifiable intangible assets, net of accumulated amortization	$ 6,818	$ 7,846
Accumulated amortization	5,626	4,998
Non-competition agreements
Acquired identifiable intangible assets
Acquired identifiable intangible assets, net of accumulated amortization	134	180
Accumulated amortization	190	544
Customer relationships
Acquired identifiable intangible assets
Acquired identifiable intangible assets, net of accumulated amortization	6,684	7,666
Accumulated amortization	$ 5,436	$ 4,454