Notes Acquired but not Retired.

No definition available.

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Namespace Prefix:	bx_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ 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 210.5-02.22(a)(1))

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

+ Details

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Balance Type:	na
Period Type:	instant

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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Data Type:	xbrli:stringItemType
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Period Type:	duration

- Definition

Date when the debt instrument is scheduled to be fully repaid, in CCYY-MM-DD format.

+ 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 210.5-02.22(a)(2))

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

+ Details

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Balance Type:	na
Period Type:	duration

- Definition

Including the current and noncurrent portions, carrying value as of the balance sheet date of Notes with the highest claim on the assets of the issuer in case of bankruptcy or liquidation (with maturities initially due after one year or beyond the operating cycle if longer). Senior note holders are paid off in full before any payments are made to junior note holders.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.7-03.16(a))

-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-03.16)

-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

+ Details

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

- Details

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- Details

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- Details

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- Details

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- Details

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- Details

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- Details

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Carrying Value and Fair Value of Blackstone Issued Notes (Parenthetical) (Detail) € in Millions, $ in Millions	9 Months Ended
	Sep. 30, 2015 USD ($)	Sep. 30, 2015 EUR (€)	Dec. 31, 2012 USD ($)
Debt Instrument [Line Items]
Senior Notes			$ 600
Notes acquired not retired			$ 15
Senior Secured Notes \| 6.625% Notes
Debt Instrument [Line Items]
Debt instrument, interest rate	6.625%	6.625%
Debt instrument, maturity date	Aug. 15, 2019
Senior Notes	$ 600
Senior Secured Notes \| 5.875% Notes
Debt Instrument [Line Items]
Debt instrument, interest rate	5.875%	5.875%
Debt instrument, maturity date	Mar. 15, 2021
Senior Notes	$ 400
Senior Secured Notes \| 4.750% Notes
Debt Instrument [Line Items]
Debt instrument, interest rate	4.75%	4.75%
Debt instrument, maturity date	Feb. 15, 2023
Senior Notes	$ 400
Senior Secured Notes \| 6.250% Notes
Debt Instrument [Line Items]
Debt instrument, interest rate	6.25%	6.25%
Debt instrument, maturity date	Aug. 15, 2042
Senior Notes	$ 250
Senior Secured Notes \| 5.000% Notes
Debt Instrument [Line Items]
Debt instrument, interest rate	5.00%	5.00%
Debt instrument, maturity date	Jun. 15, 2044
Senior Notes	$ 500
Senior Secured Notes \| 4.450% Notes
Debt Instrument [Line Items]
Debt instrument, interest rate	4.45%	4.45%
Debt instrument, maturity date	Jul. 15, 2045
Senior Notes	$ 350
Senior Secured Notes \| 2.000% Notes
Debt Instrument [Line Items]
Debt instrument, interest rate	2.00%	2.00%
Debt instrument, maturity date	May 19, 2025
Senior Notes \| €		€ 300