CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE INCOME (LOSS) (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Net revenue
Product	$ 2,280us-gaap_SalesRevenueGoodsNet	$ 394us-gaap_SalesRevenueGoodsNet	$ 90us-gaap_SalesRevenueGoodsNet
Royalty and other	3,100mosy_RoyaltyAndOtherRevenue	4,004mosy_RoyaltyAndOtherRevenue	5,992mosy_RoyaltyAndOtherRevenue
Total net revenue	5,380us-gaap_SalesRevenueNet	4,398us-gaap_SalesRevenueNet	6,082us-gaap_SalesRevenueNet
Cost of net revenue	2,318us-gaap_CostOfGoodsAndServicesSold	474us-gaap_CostOfGoodsAndServicesSold	334us-gaap_CostOfGoodsAndServicesSold
Gross profit	3,062us-gaap_GrossProfit	3,924us-gaap_GrossProfit	5,748us-gaap_GrossProfit
Operating expenses
Research and development	29,261us-gaap_ResearchAndDevelopmentExpense	23,325us-gaap_ResearchAndDevelopmentExpense	28,480us-gaap_ResearchAndDevelopmentExpense
Selling, general and administrative	6,519	6,161	8,218
Gain on sale of assets		(630)	(3,291)
Total operating expenses	35,780us-gaap_OperatingExpenses	28,856us-gaap_OperatingExpenses	33,407us-gaap_OperatingExpenses
Loss from operations	(32,718)us-gaap_OperatingIncomeLoss	(24,932)us-gaap_OperatingIncomeLoss	(27,659)us-gaap_OperatingIncomeLoss
Other income, net	143us-gaap_OtherNonoperatingIncomeExpense	209us-gaap_OtherNonoperatingIncomeExpense	155us-gaap_OtherNonoperatingIncomeExpense
Loss before income taxes	(32,575)	(24,723)	(27,504)
Income tax provision	107us-gaap_IncomeTaxExpenseBenefit	71us-gaap_IncomeTaxExpenseBenefit	110us-gaap_IncomeTaxExpenseBenefit
Net loss	(32,682)	(24,794)	(27,614)
Other comprehensive loss, net of tax:
Net unrealized gains (losses) on available-for-sale securities	(23)	2	10
Comprehensive loss	$ (32,705)us-gaap_ComprehensiveIncomeNetOfTax	$ (24,792)us-gaap_ComprehensiveIncomeNetOfTax	$ (27,604)us-gaap_ComprehensiveIncomeNetOfTax
Per Share Amounts
Basic and diluted (in dollars per share)	$ (0.66)us-gaap_EarningsPerShareBasicAndDiluted	$ (0.55)us-gaap_EarningsPerShareBasicAndDiluted	$ (0.70)us-gaap_EarningsPerShareBasicAndDiluted
Shares used in computing net loss per share
Basic and diluted (in shares)	49,528	45,246	39,176

Represents the amount of revenue earned during the period from the leasing or otherwise lending to a third party the entity's rights or title to certain property and revenues from the sale of other goods or rendering of other services, not elsewhere specified in the taxonomy; net of (reduced by) sales adjustments, returns, allowances, and discounts.

No definition available.