v2.4.0.8
Carrying Value and Fair Value of Blackstone Issued Notes (Parenthetical) (Detail) (USD $)
In Millions, unless otherwise specified
9 Months Ended
Dec. 31, 2012
Sep. 30, 2013
6.625% Notes
Sep. 30, 2013
5.875% Notes
Sep. 30, 2013
4.750% Notes
Sep. 30, 2013
6.250% Notes
Debt Instrument [Line Items]          
Debt instrument, interest rate   6.625% 5.875% 4.75% 6.25%
Debt instrument, maturity date   Aug. 15, 2019 Mar. 15, 2021 Feb. 15, 2023 Aug. 15, 2042
Senior Notes $ 600 $ 600 $ 400 $ 400 $ 250
Notes acquired not retired $ 15