Acquisition of Petsense (Details) - USD ($) $ in Thousands				12 Months Ended
	Dec. 30, 2017	Dec. 31, 2016	Sep. 29, 2016	Dec. 30, 2017	Dec. 31, 2016
Business Acquisition [Line Items]
Business Acquisition, Effective Date of Acquisition			Sep. 29, 2016
Consideration Transferred	$ 144,476
Current Assets	21,875			$ 21,875
Property and Equipment	25,519			25,519
Other intangible assets - tradename	31,300
Other Assets	428			428
Current Liabilities	(12,091)			(12,091)
Long-term liabilities	(5,489)			(5,489)
Total identifiable net assets acquired	61,542			61,542
Excess of consideration transferred over identifiable net assets acquired (goodwill)	82,934			82,934
Goodwill, Purchase Accounting Adjustments				(1,225)	$ 0
Goodwill, Acquired During Period			$ 82,900	$ 0	$ 84,159
Indefinite-lived Intangible Assets Acquired	$ 31,300	$ 31,300	$ 31,300