Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 4
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=109196051&loc=SL49130543-203045

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=109196051&loc=SL49130539-203045

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=109196051&loc=SL49130545-203045

Name:	us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

REVENUE Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 26, 2018	Sep. 26, 2018	Jun. 27, 2018	Mar. 28, 2018	Dec. 27, 2017	Sep. 27, 2017	Jun. 28, 2017	Mar. 29, 2017	Dec. 26, 2018	Dec. 27, 2017	Dec. 28, 2016
Disaggregation of Revenue [Line Items]
TOTAL REVENUE	$ 124,265	$ 119,647	$ 116,282	$ 99,116	$ 96,136	$ 94,609	$ 91,316	$ 76,749	$ 459,310	$ 358,810	$ 268,475
Shack sales
Disaggregation of Revenue [Line Items]
TOTAL REVENUE									445,589	346,388	259,350
Sales-based royalties
Disaggregation of Revenue [Line Items]
TOTAL REVENUE									13,422	11,633	8,765
Initial territory and opening fees
Disaggregation of Revenue [Line Items]
TOTAL REVENUE									$ 299	$ 789	$ 360