Stock-Based Compensation Subsequent Events (Details)	Sep. 24, 2019 USD ($)
Subsequent Event
Subsequent Event [Line Items]
Total unrecognized stock-based compensation, net of estimated forfeitures and assuming achievement of the pre-established performance goal at a target level, related to stock-based awards authorized for issuance.	$ 5,632,000

Total unrecognized stock-based compensation, net of estimated forfeitures and assuming achievement of the pre-established performance goal at a target level, related to stock-based awards authorized for issuance.

No definition available.

Name:	cmtl_TotalUnrecognizedStockBasedCompensationNetRelatedToStockBasedAwardsAuthorizedForIssuance
Namespace Prefix:	cmtl_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant