Represents the number of finite-lived intangible assets sold.

No definition available.

Name:	mosy_NumberOfFiniteLivedIntangibleAssetsSold
Namespace Prefix:	mosy_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

This element represents the valuation of patents recorded in connection with the patent sale during the reporting period.

+ References

No definition available.

+ Details

Name:	mosy_PatentsRecordedInConnectionWithPatentSaleValuation
Namespace Prefix:	mosy_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Useful life of finite-lived intangible assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

Name:	us-gaap_FiniteLivedIntangibleAssetUsefulLife
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

The cash inflow from disposal of asset without physical form usually arising from contractual or other legal rights, excluding goodwill.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Investing Activities

-URI http://asc.fasb.org/extlink&oid=6516133

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 12

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3179-108585

+ Details

Name:	us-gaap_ProceedsFromSaleOfIntangibleAssets
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The value of all consideration given or received by the Entity in the significant acquisition or disposal.

+ References

No definition available.

+ Details

Name:	us-gaap_SignificantAcquisitionsAndDisposalsAcquisitionCostsOrSaleProceeds
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Details

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

- Details

Name:	us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis=mosy_MemoryTechnologyPatentsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis=mosy_SaleOfPatentsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Patent Sale and License (Details) (USD $)	0 Months Ended		12 Months Ended	1 Months Ended
Patent Sale and License (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2014 item	Dec. 31, 2011
Patent Sale and License
Net cash proceeds from sale of assets	$ 630,000	$ 3,437,000
Memory technology patents
Patent Sale and License
Number of intangible assets sold			73
Sale of memory technology patents \| Memory technology patents
Patent Sale and License
Cash consideration				35,000,000
Valuation of right to use patents				$ 800,000
Estimated useful life				7 years
Sale of memory technology patents \| Domestic memory technology patents
Patent Sale and License
Number of intangible assets sold				43
Sale of memory technology patents \| Foreign memory technology patents
Patent Sale and License
Number of intangible assets sold				30