v2.4.0.8

Derivative Financial Instruments - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013
Derivative [Line Items]
Net gain (loss) on hedged items	$ 64.2
Hedged gain (loss) remaining amortization period end date	Aug. 15, 2019

X

- Definition

Amortization Of Hedged Gain Loss Remaining Period End Date

+ References

No definition available.

+ Details

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Namespace Prefix:	bx_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	instant

X

- Details

Name:	us-gaap_DerivativeLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Total amount of gain (loss) derived from fair value hedges recognized in earnings in the period.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 50

-Paragraph 4C

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=7476318&loc=SL5624171-113959

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration