v2.4.0.8

Regulated Entities - Additional Information (Detail) (USD $) In Millions, unless otherwise specified | Dec. 31, 2013
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Regulatory Matters [Line Items] |
Consolidated entities net assets restricted as to payment of cash dividends and advances to partnership | $ 24.3

X
- Definition Consolidated entities' net assets restricted as to payment of cash dividends and advances to partnership. + References No definition available. + Details
Name: | bx_ConsolidatedEntitiesNetAssetsRestrictedAsToPaymentOfCashDividendsAndAdvancesToPartnership
Namespace Prefix: | bx_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

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