Schedule of deferred tax assets and liabilities (Details) - USD ($) $ in Thousands	Dec. 29, 2017	Dec. 30, 2016
Deferred tax assets:
Receivables and inventory	$ 3,969	$ 5,230
Accrued expenses	1,542	2,122
Self-insurance reserves	2,179	2,515
Net operating loss carryforwards	1,191	2,498
Stock compensation	1,017	1,122
Other	1,696	1,213
Total deferred tax assets	11,594	14,700
Deferred tax liabilities:
Property & equipment	(1,701)	(1,759)
Intangible assets	(10,784)	(12,962)
Contingent earn-out liabilities	(3,646)	(5,020)
Prepaid expenses and other	(1,189)	(1,917)
Total deferred tax liabilities	(17,320)	(21,658)
Valuation allowance	(289)	0
Total net deferred tax liability	$ (6,015)	$ (6,958)