Consolidated Balance Sheets and Statements of Operations and Comprehensive Loss Components (Details 3) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Accrued expenses and other:
Accrued wages and employee benefits	$ 1,026	$ 818
Employee stock purchase plan withholdings	357	286
IC development wafer costs	203mosy_IcDevelopmentWaferCosts
Professional fees	123us-gaap_AccruedProfessionalFeesCurrent	61us-gaap_AccruedProfessionalFeesCurrent
Deferred revenue	4us-gaap_DeferredRevenue	170us-gaap_DeferredRevenue
Other	637us-gaap_OtherAccruedLiabilitiesCurrent	744us-gaap_OtherAccruedLiabilitiesCurrent
Total	2,350us-gaap_AccruedLiabilitiesCurrent	2,079us-gaap_AccruedLiabilitiesCurrent
Other income, net:
Interest income	155	174	171
Other income (expense), net	(12)	35	(16)
Total	$ 143us-gaap_OtherNonoperatingIncomeExpense	$ 209us-gaap_OtherNonoperatingIncomeExpense	$ 155us-gaap_OtherNonoperatingIncomeExpense

Represents IC development wafer costs.

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The sum of the carrying amounts, as of the balance sheet date, of other income and expense amounts, resulting from ancillary business-related activities, which have not been itemized or categorized in the footnotes to the financial statements and are a component of other income and expense.

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Carrying value as of the balance sheet date of obligations incurred and payable, pertaining to costs that are statutory in nature, are incurred on contractual obligations, or accumulate over time and for which invoices have not yet been received or will not be rendered. Examples include taxes, interest, rent and utilities. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

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Carrying value as of the balance sheet date of obligations incurred through that date and payable for professional fees, such as for legal and accounting services received. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

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Aggregate carrying value as of the balance sheet date of the liabilities for stock option plans and other equity-based compensation arrangements payable within one year (or the operating cycle, if longer).

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Amount of deferred revenue as of balance sheet date. Deferred revenue represents collections of cash or other assets related to a revenue producing activity for which revenue has not yet been recognized. Generally, an entity records deferred revenue when it receives consideration from a customer before achieving certain criteria that must be met for revenue to be recognized in conformity with GAAP.

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Total of the carrying values as of the balance sheet date of obligations incurred through that date and payable for obligations related to services received from employees, such as accrued salaries and bonuses, payroll taxes and fringe benefits. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

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The net amount of nonoperating interest income (expense).

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Carrying value as of the balance sheet date of obligations incurred through that date and payable arising from transactions not otherwise specified in the taxonomy. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

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The net amount of other income and expense amounts, the components of which are not separately disclosed on the income statement, resulting from ancillary business-related activities (that is, excluding major activities considered part of the normal operations of the business) also known as other nonoperating income (expense) recognized for the period. Such amounts may include: (a) dividends, (b) interest on securities, (c) net gains or losses on securities, (d) unusual costs, (e) gains or losses on foreign exchange transactions, and (f) miscellaneous other income and expense items.

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