v2.4.1.9

Organization - Additional Information (Detail) | 3 Months Ended
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Mar. 31, 2015 Times Segment Person
Organization [Line Items] |
Number of business segments | 5 us-gaap_NumberOfOperatingSegments
Number of Blackstone founders managing the Partnership | 1 bx_NumberOfCompanyFoundersManagingPartnership
Number of times per year, holders of limited partnership interest can exchange their limited partnership interest | 4 bx_NumberOfTimesHoldersOfInterestCanExchangeTheirLimitedPartnershipInterestPerYear
Partnership Unit to Blackstone Common Unit ratio | 100.00%bx_LimitedPartnershipToCommonStockConversionRatio

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- Definition Limited Partnership To Common Stock Conversion Ratio + References No definition available. + Details
Name: | bx_LimitedPartnershipToCommonStockConversionRatio
Namespace Prefix: | bx_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

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- Definition Number Of Company Founders Managing Partnership + References No definition available. + Details
Name: | bx_NumberOfCompanyFoundersManagingPartnership
Namespace Prefix: | bx_
Data Type: | xbrli:positiveIntegerItemType
Balance Type: | na
Period Type: | duration

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- Definition Number Of Times Holders Of Interest Can Exchange Their Limited Partnership Interest Per Year + References No definition available. + Details
Name: | bx_NumberOfTimesHoldersOfInterestCanExchangeTheirLimitedPartnershipInterestPerYear
Namespace Prefix: | bx_
Data Type: | xbrli:positiveIntegerItemType
Balance Type: | na
Period Type: | duration

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- Details
Name: | bx_OrganizationLineItems
Namespace Prefix: | bx_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

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- Definition Number of operating segments. An operating segment is a component of an enterprise: (a) that engages in business activities from which it may earn revenues and incur expenses (including revenues and expenses relating to transactions with other components of the same enterprise), (b) whose operating results are regularly reviewed by the enterprise's chief operating decision maker to make decisions about resources to be allocated to the segment and assess its performance, and (c) for which discrete financial information is available. An operating segment may engage in business activities for which it has yet to earn revenues, for example, start-up operations may be operating segments before earning revenues. + References No definition available. + Details
Name: | us-gaap_NumberOfOperatingSegments
Namespace Prefix: | us-gaap_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration