INCOME TAXES - Unrecognized tax benefits (Details) - USD ($)	Dec. 28, 2019	Dec. 29, 2018
Interest and penalties recognized on the liability for unrecognized tax benefits
Amount of unrecognized tax benefits that would affect the effective tax rates	$ 0	$ 0

The total amount of unrecognized tax benefits that, if recognized, would affect the effective tax rate.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 15A
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=84230637&loc=SL6600010-109319

Name:	us-gaap_UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant