Document and Entity Information - shares
9 Months Ended
Sep. 30, 2019
Oct. 15, 2019
Document Information [Line Items]    
Document Type 10-Q  
Amendment Flag false  
Document Period End Date Sep. 30, 2019  
Document Fiscal Year Focus 2019  
Document Fiscal Period Focus Q3  
Trading Symbol MSTR  
Entity Registrant Name MICROSTRATEGY INC  
Entity Central Index Key 0001050446  
Entity Interactive Data Current Yes  
Current Fiscal Year End Date --12-31  
Entity Filer Category Large Accelerated Filer  
Entity Small Business false  
Entity Emerging Growth Company false  
Title of 12(b) Security Class A common stock, par value $0.001 per share  
Security Exchange Name NASDAQ  
Entity Current Reporting Status Yes  
Entity Shell Company false  
Entity File Number 000-24435  
Entity Incorporation, State or Country Code DE  
Entity Tax Identification Number 51-0323571  
Entity Address, Address Line One 1850 Towers Crescent Plaza  
Entity Address, City or Town Tysons Corner  
Entity Address, State or Province VA  
Entity Address, Postal Zip Code 22182  
City Area Code (703)  
Local Phone Number 848-8600  
Document Quarterly Report true  
Document Transition Report false  
Class A    
Document Information [Line Items]    
Entity Common Stock, Shares Outstanding   8,231,895
Class B    
Document Information [Line Items]    
Entity Common Stock, Shares Outstanding   2,035,184