Warrants (Fair Value of Warrants) (Details) $ in Thousands	3 Months Ended
Mar. 31, 2022 USD ($)
Warrants [Abstract]
Change in Fair Value of common stock warrant liability	$ 1,146

Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Change in Fair Value

No definition available.

Name:	eman_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityChangeInFairValue
Namespace Prefix:	eman_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration