v2.4.1.9

Commitments and Contingencies - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Commitments and Contingencies [Line Items]
Total rental expenses under operating lease agreements	$ 30.4us-gaap_OperatingLeasesRentExpenseNet	$ 28.3us-gaap_OperatingLeasesRentExpenseNet	$ 26.4us-gaap_OperatingLeasesRentExpenseNet
Northern Virginia Office Space
Commitments and Contingencies [Line Items]
Office space area leased under the agreement	233,000us-gaap_AreaOfRealEstateProperty / us-gaap_LeaseArrangementTypeAxis = mstr_NorthernVirginiaOfficeSpaceMember
Lease expiration date	2020-12
Deferred rent included in other long-term liabilities	18.9us-gaap_DeferredRentCreditNoncurrent / us-gaap_LeaseArrangementTypeAxis = mstr_NorthernVirginiaOfficeSpaceMember	20.1us-gaap_DeferredRentCreditNoncurrent / us-gaap_LeaseArrangementTypeAxis = mstr_NorthernVirginiaOfficeSpaceMember
Deferred rent included in current accrued expenses	$ 3.0us-gaap_DeferredRentCreditCurrent / us-gaap_LeaseArrangementTypeAxis = mstr_NorthernVirginiaOfficeSpaceMember	$ 2.8us-gaap_DeferredRentCreditCurrent / us-gaap_LeaseArrangementTypeAxis = mstr_NorthernVirginiaOfficeSpaceMember
Northern Virginia Office, Additional Office Space | 2014 Restructuring Plan
Commitments and Contingencies [Line Items]
Lease expiration date	2015-02
Office space ceased to be used	19,000mstr_AreaOfRealEstatePropertyCeasedToBeUsed / us-gaap_LeaseArrangementTypeAxis = mstr_NorthernVirginiaOfficeAdditionalOfficeSpaceMember / us-gaap_RestructuringPlanAxis = mstr_TwentyFourteenRestructuringPlanMember

X

- Definition

Area of Real Estate Property Ceased to be used

+ References

No definition available.

+ Details

Name:	mstr_AreaOfRealEstatePropertyCeasedToBeUsed
Namespace Prefix:	mstr_
Data Type:	num:areaItemType
Balance Type:	na
Period Type:	instant

X

- Details

Name:	mstr_CommitmentsAndContingenciesLineItems
Namespace Prefix:	mstr_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Date which lease or group of leases is set to expire, in YYYY-MM format.

+ References

No definition available.

+ Details

Name:	mstr_LeaseExpirationMonthYear
Namespace Prefix:	mstr_
Data Type:	xbrli:gYearMonthItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Area of a real estate property.

+ References

No definition available.

+ Details

Name:	us-gaap_AreaOfRealEstateProperty
Namespace Prefix:	us-gaap_
Data Type:	num:areaItemType
Balance Type:	na
Period Type:	instant

X

- Definition

For a classified balance sheet, the cumulative difference as of the balance sheet date between the payments required by a lease agreement and the rental income or expense recognized on a straight-line basis, or other systematic and rational basis more representative of the time pattern in which use or benefit is granted or derived from the leased property, expected to be recognized in income or expense, by the lessor or lessee, respectively, within one year of the balance sheet date.

+ 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 210.5-02.20)

-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 840

-SubTopic 20

-Section 25

-Paragraph 2

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=7501430&loc=d3e39927-112707

+ Details

Name:	us-gaap_DeferredRentCreditCurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

X

- Definition

For a classified balance sheet, the cumulative difference between the rental income or payments required by a lease agreement and the rental income or expense recognized on a straight-line basis, or other systematic and rational basis more representative of the time pattern in which use or benefit is granted or derived from the leased property, expected to be recognized in income or expense, by the lessor or lessee, respectively, more than one year after the balance sheet date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 840

-SubTopic 20

-Section 25

-Paragraph 2

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=7501430&loc=d3e39927-112707



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 210.5-02.26(c))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

Name:	us-gaap_DeferredRentCreditNoncurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

X

- Definition

Rental expense for the reporting period incurred under operating leases, including minimum and any contingent rent expense, net of related sublease income.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 840

-SubTopic 20

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6453985&loc=d3e41499-112717

+ Details

Name:	us-gaap_OperatingLeasesRentExpenseNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Details

Name:	us-gaap_LeaseArrangementTypeAxis=mstr_NorthernVirginiaOfficeAdditionalOfficeSpaceMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_LeaseArrangementTypeAxis=mstr_NorthernVirginiaOfficeSpaceMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: