Acquisitions (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 30, 2017	Dec. 31, 2016	Dec. 26, 2015
Assets acquired and liabilities assumed:
Goodwill	$ 21,548	$ 21,456
Total consideration paid	(1,500)
Gain on bargain purchase	256	$ 0	$ 0
Goalsetter & Onix [Member]
Assets acquired and liabilities assumed:
Accounts receivable	795
Inventories	966
Other assets	50
Goodwill	5,172
Intangible assets	6,286
Accounts payable	(271)
Other liabilities	(74)
Income tax liability - deferred	(2,046)
Gain on bargain purchase	10,878
Acquisition One [Member]
Assets acquired and liabilities assumed:
Accounts receivable	852
Inventories	737
Other assets	64
Intangible assets	413
Total fair value of assets acquired	2,066
Total liabilities assumed	(563)
Net assets acquired	1,503
Total consideration paid	(1,101)
Gain before deferred income tax liability	402
Income tax liability - deferred	(146)
Gain on bargain purchase	$ 256