Selected Quarterly Financial Data - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended
Dec. 31, 2014
Quarterly Financial Information [Line Items]
Increase in income from continuing operations as result of reduction in its accrued bonus expense	$ 7.4

The amount of increase in income from continuing operations as a result of a reduction in accrued bonus expense.

No definition available.

Name:	mstr_IncreaseInIncomeFromContinuingOperationsFromReductionInAccruedBonusExpense
Namespace Prefix:	mstr_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration