General Commitments (Narrative) (Details)	Aug. 02, 2018 USD ($)
Contingencies and General Commitments [Abstract]
Sale of building, purchase agreement, consideration amount	$ 10,000,000
Purchase agreement, buyer to complete due diligence, period	180 days

Sale of Property, Purchase Agreement, Consideration Amount

No definition available.

Name:	jcs_SaleOfPropertyPurchaseAgreementConsiderationAmount
Namespace Prefix:	jcs_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration