XML 52 R39.htm IDEA: XBRL DOCUMENT
v3.8.0.1

Stock-Based Compensation - Narrative (Details) |  |  |  |  | 1 Months Ended | 3 Months Ended | 9 Months Ended | 12 Months Ended |  |
--- | --- | --- | --- | --- | --- | --- | --- | --- | --- | ---
Aug. 31, 2016 USD ($) shares | Aug. 23, 2016 USD ($) $ / shares shares | Feb. 29, 2016 USD ($) shares | Jan. 01, 2016 shares | May 31, 2015 shares | Jun. 30, 2014 shares | Jun. 30, 2010 USD ($) item shares | Sep. 30, 2017 USD ($) $ / shares shares | Mar. 31, 2017 $ / shares shares | Sep. 30, 2016 USD ($) | Sep. 30, 2017 USD ($) $ / shares shares | Sep. 30, 2016 USD ($) shares | Dec. 31, 2016 USD ($) $ / shares shares | Dec. 31, 2015 USD ($) $ / shares shares | Dec. 31, 2014 USD ($) $ / shares shares | Jun. 30, 2017 $ / shares shares | Dec. 31, 2013 $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award, Additional General Disclosures [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Options expired in relation to the Offer |  | 456,995 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Shares issued in Replacement Offering |  | 334,027 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Shares eligible for purchase via options |  | 113,531 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Weighted-average exercise price (in dollars per share) | $ / shares |  | $ 7.20 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Vesting period of replacement options |  | 3 years |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Incremental charge resulting from the plan modification | $ |  | $ 926,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Amortization period of incremental charge |  | 3 years |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Options |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Additional General Disclosures [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Unamortized compensation cost, net of expected forfeitures | $ |  |  |  |  |  |  |  | $ 1,100,000 |  |  | $ 1,100,000 |  | $ 2,600,000 |  |  |  |
Weighted average expected period over which the expense is to be recognized |  |  |  |  |  |  |  |  |  |  | 1 year 10 months 24 days |  | 2 years 7 months 6 days |  |  |  |
Fair value of vested options and awards | $ |  |  |  |  |  |  |  |  |  |  |  |  | $ 2,000,000 |  |  |  |
Tax benefits associated with exercise of stock options | $ |  |  |  |  |  |  |  | 0 |  | $ 0 | $ 0 | $ 0 | 0 | $ 0 | $ 0 |  |
Stock options exercised |  |  |  |  |  |  |  |  |  |  | 0 | 0 |  |  |  |  |
Intrinsic value of awards exercised | $ |  |  |  |  |  |  |  |  |  |  |  |  | 0 | $ 300,000 | $ 800,000 |  |
RSU's |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Additional General Disclosures [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Unamortized compensation cost, net of expected forfeitures | $ |  |  |  |  |  |  |  |  |  |  |  |  | $ 600,000 |  |  |  |
Weighted average expected period over which the expense is to be recognized |  |  |  |  |  |  |  |  |  |  | 1 year 4 months 24 days |  | 2 years |  |  |  |
Total intrinsic value of the restricted stock units outstanding | $ |  |  |  |  |  |  |  | $ 400,000 |  |  | $ 400,000 |  |  |  |  |  |
Employee stock purchase plan |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Additional General Disclosures [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Number of shares reserved for issuance |  |  |  |  |  |  | 200,000 |  |  |  |  |  |  |  |  |  |
Increase in number of shares reserved for issuance |  |  |  |  | 200,000 |  |  |  |  |  |  |  |  |  |  |  |
Number of offering periods | item |  |  |  |  |  |  | 2 |  |  |  |  |  |  |  |  |  |
Offering period |  |  |  |  |  |  | 6 months |  |  |  |  |  |  |  |  |  |
Purchase price to be paid by participants as a percentage of price per share either at the beginning or the end of each six-month offering period, whichever is less |  |  |  |  |  |  | 85.00% |  |  |  |  |  |  |  |  |  |
Shares of common stock issued under the plan | 31,900 |  | 37,300 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Aggregate purchase price of shares issued | $ | $ 167,000 |  | $ 197,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Shares authorized and unissued |  |  |  |  |  |  |  |  |  |  |  |  | 150,000 |  |  |  |
Employee stock purchase plan | Maximum |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Additional General Disclosures [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Maximum amount of shares that eligible employee may purchase annually (in dollars) | $ |  |  |  |  |  |  | $ 25,000 |  |  |  |  |  |  |  |  |  |
Inducement Stock Options |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Additional General Disclosures [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Stock options exercised |  |  |  |  |  |  |  |  |  |  |  |  |  | 52,000 | 7,000 |  |
Weighted-average exercise price (in dollars per share) | $ / shares |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 43.74 | $ 36.78 |  | $ 44.23
Number of shares outstanding |  |  |  |  |  |  |  |  |  |  |  |  |  | 164,000 | 223,000 |  | 318,000
Equity Incentive Plan2010 [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Additional General Disclosures [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Term of Plan |  |  |  |  |  |  |  |  |  |  |  |  | 10 years |  |  |  |
Weighted-average exercise price (in dollars per share) | $ / shares |  |  |  |  |  |  |  | $ 16.47 | $ 14.06 |  | $ 16.47 |  |  |  |  | $ 16.04 |
Number of shares reserved for issuance |  |  |  |  |  |  |  |  |  |  |  |  |  | 400,000 |  |  |
Increase in number of shares reserved for issuance |  |  |  | 50,000 |  |  |  |  | 50,000 |  |  |  |  |  |  |  |
Shares authorized and unissued |  |  |  |  |  |  |  | 81,000 | 183,000 |  | 81,000 |  |  |  |  | 392,000 |
Number of shares outstanding |  |  |  |  |  |  |  | 248,000 | 508,000 |  | 248,000 |  |  |  |  | 336,000 |
Equity Incentive Plan2010 [Member] | Options |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Additional General Disclosures [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Maximum annual option grants or other awards to the entity's non-employee directors (in shares) |  |  |  |  |  |  |  |  |  |  |  |  | 4,000 |  |  |  |
Maximum one-time grant of an option or other awards to the entitiy's non employee directors (in shares) |  |  |  |  |  |  |  |  |  |  |  |  | 12,000 |  |  |  |
Maximum term of options granted |  |  |  |  |  |  |  |  |  |  |  |  | 10 years |  |  |  |
Minimum percentage of voting rights required for applicability of a specific expriation term |  |  |  |  |  |  |  |  |  |  |  |  | 10.00% |  |  |  |
Maximum expiration term of options granted |  |  |  |  |  |  |  |  |  |  |  |  | 5 years |  |  |  |
Shares issued in Replacement Offering |  |  |  |  |  |  |  |  | 1,000 |  |  |  |  |  |  |  |
Weighted-average exercise price (in dollars per share) | $ / shares |  |  |  |  |  |  |  |  |  |  |  |  | $ 13.88 |  |  |  |
Vesting period of replacement options |  |  |  |  |  |  |  |  |  |  |  |  | 4 years |  |  |  |
Increase in number of shares reserved for issuance |  |  |  |  |  | 150,000 |  |  |  |  |  |  | 50,000 | 50,000 | 200,000 |  |
Shares authorized and unissued |  |  |  |  |  |  |  |  |  |  |  |  | 114,000 |  |  |  |
Number of shares outstanding |  |  |  |  |  |  |  |  |  |  |  |  | 522,000 |  |  |  |
Equity Incentive Plan2010 [Member] | Options | Minimum |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Additional General Disclosures [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Term of Plan |  |  |  |  |  |  |  |  |  |  |  |  | 6 years |  |  |  |
Equity Incentive Plan2010 [Member] | Options | Maximum |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Additional General Disclosures [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Term of Plan |  |  |  |  |  |  |  |  |  |  |  |  | 10 years |  |  |  |
Amended 2000 Plan [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Additional General Disclosures [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Shares authorized and unissued |  |  |  |  |  |  |  |  |  |  |  |  | 0 |  |  |  |
Mosy Plans [Member] | Options |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Additional General Disclosures [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Stock options exercised |  |  |  |  |  |  |  |  |  |  |  |  |  | 8,000 | 41,000 |  |
Options expired in relation to the Offer |  |  |  |  |  |  |  |  |  |  |  |  | 58,000 |  |  |  |
Shares issued in Replacement Offering |  |  |  |  |  |  |  |  |  |  |  |  | 384,000 | 154,000 | 17,000 |  |
Weighted-average exercise price (in dollars per share) | $ / shares |  |  |  |  |  |  |  |  |  |  |  |  | $ 13.88 | $ 35.14 | $ 38.73 |  | $ 38.64
Shares authorized and unissued |  |  |  |  |  |  |  |  |  |  |  |  | 114,000 | 106,000 | 176,000 |  | 42,000
Number of shares outstanding |  |  |  |  |  |  |  |  |  |  |  |  | 522,000 | 675,000 | 599,000 |  | 672,000
Mosy Plans [Member] | RSU's |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Additional General Disclosures [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Total intrinsic value of the restricted stock units outstanding | $ |  |  |  |  |  |  |  |  |  |  |  |  | $ 300,000 |  |  |  |

X
- Definition Fair Value equity-based compensation awards and options vested. + References No definition available. + Details
Name: | mosy_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsIncludingOptionsAggregateIntrinsicValueVested
Namespace Prefix: | mosy_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Represents the highest amount of shares that an eligible employee can purchase under the plan per period. + References No definition available. + Details
Name: | mosy_ShareBasedCompensationArrangementByShareBasedPaymentAwardMaximumAmountOfSharesPerEmployee
Namespace Prefix: | mosy_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Represents the maximum expiration term of awards granted under the plan. + References No definition available. + Details
Name: | mosy_ShareBasedCompensationArrangementByShareBasedPaymentAwardMaximumExpirationTerm
Namespace Prefix: | mosy_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Represents the maximum expiration term of awards granted applicable to holders of a specific percentage of voting rights of all classes of outstanding stock on the date of grant. + References No definition available. + Details
Name: | mosy_ShareBasedCompensationArrangementByShareBasedPaymentAwardMaximumExpirationTermApplicableToHoldersOfSpecificPercentageOfVotingRightsOfAllClasses
Namespace Prefix: | mosy_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Represents the minimum percentage of voting rights of all classes of outstanding stock, on the date of grant, held by the persons to whom awards were granted for applicability of specific expiration term of options. + References No definition available. + Details
Name: | mosy_ShareBasedCompensationArrangementByShareBasedPaymentAwardMinimumVotingPowerPercentageForApplicabilityOfSpecificExpirationTerm
Namespace Prefix: | mosy_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Represents the number of offering periods per annum over which an employee may purchase the shares of common stock of the entity under the stock-based compensation arrangements. + References No definition available. + Details
Name: | mosy_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfOfferingPeriodsPerYear
Namespace Prefix: | mosy_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Represents the shares reserved for grant under option or other awards to the entity's non-employee directors annually under the share-based compensation plan. + References No definition available. + Details
Name: | mosy_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesReservedForAnnualGrantToNonemployeeDirectors
Namespace Prefix: | mosy_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition Represents the shares reserved for one-time grant under option or other awards to the entity's non-employee directors under the share-based compensation plan. + References No definition available. + Details
Name: | mosy_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesReservedForOneTimeGrantToNonemployeeDirectors
Namespace Prefix: | mosy_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition Represents the offering period over which an employee may purchase the shares of common stock of the entity under the stock-based compensation arrangements. + References No definition available. + Details
Name: | mosy_ShareBasedCompensationArrangementByShareBasedPaymentAwardOfferingPeriod
Namespace Prefix: | mosy_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Share-based Compensation Arrangement by Share-based Payment Award, Options to Purchase Shares + References No definition available. + Details
Name: | mosy_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsToPurchaseShares
Namespace Prefix: | mosy_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition Share-based Compensation Arrangement by Share-based Payment Award, Plan Modification, Incremental Compensation Cost, Amortization Period + References No definition available. + Details
Name: | mosy_ShareBasedCompensationArrangementByShareBasedPaymentAwardPlanModificationIncrementalCompensationCostAmortizationPeriod
Namespace Prefix: | mosy_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Represents the term of share-based compensation plans. + References No definition available. + Details
Name: | mosy_ShareBasedCompensationArrangementByShareBasedPaymentAwardTermOfPlan
Namespace Prefix: | mosy_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Weighted average period over which unrecognized compensation is expected to be recognized for equity-based compensation plans, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (i) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
Name: | us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Unrecognized cost of unvested options awarded to employees as compensation. + References No definition available. + Details
Name: | us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Disclosure of the aggregate tax benefit realized from the exercise of stock options and the conversion of similar instruments during the annual period. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (j) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
Name: | us-gaap_EmployeeServiceShareBasedCompensationTaxBenefitRealizedFromExerciseOfStockOptions
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAdditionalGeneralDisclosuresAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Period which an employee's right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of additional shares authorized for issuance under an established share-based compensation plan. + References No definition available. + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfAdditionalSharesAuthorized
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition The maximum number of shares (or other type of equity) originally approved (usually by shareholders and board of directors), net of any subsequent amendments and adjustments, for awards under the equity-based compensation plan. As stock or unit options and equity instruments other than options are awarded to participants, the shares or units remain authorized and become reserved for issuance under outstanding awards (not necessarily vested). + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a)(3) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition Amount of accumulated difference between fair value of underlying shares on dates of exercise and exercise price on options exercised (or share units converted) into shares. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (d)(2) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Number of options or other stock instruments for which the right to exercise has lapsed under the terms of the plan agreements. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(1)(iv)(4) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExpirationsInPeriod
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of options outstanding, including both vested and non-vested options. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(1)(i)-(ii) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition Weighted average price at which grantees can acquire the shares reserved for issuance under the stock option plan. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(1)(i) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice
Namespace Prefix: | us-gaap_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | instant

X
- Definition An excess of the fair value of the modified award over the fair value of the award immediately before the modification. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (h)(2)(iii) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardPlanModificationIncrementalCompensationCost
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Number of share instruments newly issued under a share-based compensation plan. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesIssuedInPeriod
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition Intrinsic value of equity-based compensation awards outstanding. Excludes stock and unit options. + References No definition available. + Details
Name: | us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsAggregateIntrinsicValueOutstanding
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Purchase price of common stock expressed as a percentage of its fair value. + References No definition available. + Details
Name: | us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardPurchasePriceOfCommonStockPercent
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of shares issued during the period as a result of an employee stock purchase plan. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21463-112644 Reference 2: 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(29)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 3: 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(28)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.3-04) -URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770 + Details
Name: | us-gaap_StockIssuedDuringPeriodSharesEmployeeStockPurchasePlans
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of share options (or share units) exercised during the current period. + 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(29)) -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 505 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21463-112644 Reference 3: 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(28)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.3-04) -URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(1)(iv)(2) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
Name: | us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition Aggregate change in value for stock issued during the period as a result of employee stock purchase plan. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21463-112644 Reference 2: 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(28)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 3: 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(29)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.3-04) -URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770 + Details
Name: | us-gaap_StockIssuedDuringPeriodValueEmployeeStockPurchasePlan
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Details
Name: | us-gaap_AwardTypeAxis=mosy_EmployeeAndDirectorsStockOptionsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_AwardTypeAxis=us-gaap_RestrictedStockUnitsRSUMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_AwardTypeAxis=us-gaap_EmployeeStockMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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

X
- Details
Name: | us-gaap_AwardTypeAxis=mosy_InducementStockOptionsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_PlanNameAxis=mosy_EquityIncentivePlan2010Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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

X
- Details
Name: | us-gaap_PlanNameAxis=mosy_Amended2000PlanMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_PlanNameAxis=mosy_MosyPlansMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |