RIGHTS AGREEMENT (Details)	12 Months Ended
Dec. 31, 2018 Right
RIGHTS AGREEMENT [Abstract]
Number of preferred share purchase rights declared as dividend for each outstanding share of common stock	1
Minimum combined ownership of outstanding shares of common stock by acquiring person	20.00%

Minimum percentage of the Combined Ownership of the outstanding shares of Common Stock by Acquiring Person for the evidence of the Rights to be the rights certificate.

No definition available.

Name:	cemi_MinimumCombinedOwnershipOfOutstandingSharesOfCommonStockByAcquiringPerson
Namespace Prefix:	cemi_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant