Amount of lessee's right to use underlying asset under operating lease.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 45
-Paragraph 1
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=77888419&loc=SL77918627-209977

Name:	us-gaap_OperatingLeaseRightOfUseAsset
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

New Accounting Standards and Changes in Accounting Principles (Details Textual) - USD ($) $ in Thousands	Mar. 23, 2019	Dec. 31, 2018	Dec. 29, 2018	Mar. 24, 2018
Operating Lease, Right-of-Use Asset	$ 878		$ 0	$ 0
Accounting Standards Update 2016-02 [Member]
Operating Lease, Right-of-Use Asset		$ 985