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Subsequent Events - Additional Information (Detail) (USD $)
In Millions, except Share data, unless otherwise specified
 12 Months Ended 0 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Feb. 26, 2015
Subsequent Event [Line Items]        
Stock option awards granted 745,000us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross 600,000us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross 0us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross  
Unrecognized share-based compensation expense $ 46.6us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions      
Subsequent Event | Amendment No. 1 to the 2013 Plan | Class A        
Subsequent Event [Line Items]        
Stock option awards granted       200,000us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross
/ us-gaap_PlanNameAxis
= mstr_AmendedPlanMember
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
/ us-gaap_SubsequentEventTypeAxis
= us-gaap_SubsequentEventMember
Unrecognized share-based compensation expense       $ 13.6us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions
/ us-gaap_PlanNameAxis
= mstr_AmendedPlanMember
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
/ us-gaap_SubsequentEventTypeAxis
= us-gaap_SubsequentEventMember
Vesting period, in years       4 years