Debt and Related Warrants - 2017 Facility - Additional Information (Details) - 2017 Credit Facility $ in Millions	May 04, 2017 USD ($) item
Debt
Loan agreement amount \| $	$ 12.0
End-of-term fee (as a percent)	6.00%
Prime Rate
Debt
Interest rate, negative basis spread percentage	0.75%
Interest rate	3.75%
Prime Rate \| Minimum
Debt
Number of interest and principal payments	24
Prime Rate \| Maximum
Debt
Number of interest and principal payments	36

Percentage points subtracted from the reference rate to compute the variable rate on the debt instrument.

No definition available.

Name:	mram_DebtInstrumentNegativeBasisSpreadOnVariableRate
Namespace Prefix:	mram_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The percentage of the amount borrowed that must be paid when the loan is prepaid or repaid.

+ References

No definition available.

+ Details

Name:	mram_EndOfTermFeePercentage
Namespace Prefix:	mram_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Number of interest and principal payments.

+ References

No definition available.

+ Details

Name:	mram_NumberOfInterestAndPrincipalPayments
Namespace Prefix:	mram_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Effective interest rate for the funds borrowed under the debt agreement considering interest compounding and original issue discount or premium.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(1))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=64930785&loc=d3e28551-108399

+ Details

Name:	us-gaap_DebtInstrumentInterestRateEffectivePercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

+ Details

Name:	us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Details

Name:	us-gaap_CreditFacilityAxis=mram_SiliconValleyBankCreditFacilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_VariableRateAxis=us-gaap_PrimeRateMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RangeAxis=us-gaap_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RangeAxis=us-gaap_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: