v2.4.1.9

Employee Benefit Plan - Additional Information (Detail) (USD $) | 12 Months Ended
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Dec. 31, 2014 | Dec. 31, 2013 | Dec. 31, 2012
Defined Contribution Plan Disclosure [Line Items] |  |  |
Maximum employee contribution to 401k | 50.00%us-gaap_DefinedContributionPlanMaximumAnnualContributionsPerEmployeePercent |  |
Employer match for first 6% contributed by plan participant | 50.00%us-gaap_DefinedContributionPlanEmployerMatchingContributionPercentOfMatch |  |
Maximum contribution by participant that employer will match at 50% | 6.00%us-gaap_DefinedContributionPlanEmployerMatchingContributionPercent |  |
Maximum annual contribution by employer | $ 3,000mstr_AnnualMaximumContributionToParticipant401kPlan |  |
Employer contribution to the plan | $ 2,900,000us-gaap_DefinedContributionPlanEmployerDiscretionaryContributionAmount | $ 2,700,000us-gaap_DefinedContributionPlanEmployerDiscretionaryContributionAmount | $ 2,600,000us-gaap_DefinedContributionPlanEmployerDiscretionaryContributionAmount

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- Definition Annual Maximum Contribution To Participant 401k Plan + References No definition available. + Details
Name: | mstr_AnnualMaximumContributionToParticipant401kPlan
Namespace Prefix: | mstr_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Details
Name: | us-gaap_DefinedContributionPlanDisclosureLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of discretionary contributions made by an employer to a defined contribution plan. + References No definition available. + Details
Name: | us-gaap_DefinedContributionPlanEmployerDiscretionaryContributionAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Percentage of employees' gross pay for which the employer contributes a matching contribution to a defined contribution plan. + References No definition available. + Details
Name: | us-gaap_DefinedContributionPlanEmployerMatchingContributionPercent
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage employer matches of the employee's percentage contribution matched. + References No definition available. + Details
Name: | us-gaap_DefinedContributionPlanEmployerMatchingContributionPercentOfMatch
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Maximum percentage of employee gross pay the employee may contribute to a defined contribution plan. + References No definition available. + Details
Name: | us-gaap_DefinedContributionPlanMaximumAnnualContributionsPerEmployeePercent
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration