Derivative Financial Instruments - Unrealized and Realized Gains (Losses) on Derivative Contracts (Detail) (USD $)
In Thousands, unless otherwise specified
3 Months Ended 6 Months Ended 9 Months Ended 3 Months Ended 6 Months Ended 9 Months Ended 3 Months Ended 6 Months Ended 9 Months Ended 3 Months Ended 6 Months Ended 9 Months Ended 3 Months Ended 6 Months Ended 9 Months Ended 3 Months Ended 6 Months Ended 9 Months Ended 3 Months Ended
Aug. 31, 2014
Successor [Member]
Aug. 31, 2013
Successor [Member]
Aug. 31, 2013
Successor [Member]
Aug. 31, 2014
Successor [Member]
Aug. 31, 2014
Successor [Member]
Interest rate contracts [Member]
Aug. 31, 2013
Successor [Member]
Interest rate contracts [Member]
Aug. 31, 2013
Successor [Member]
Interest rate contracts [Member]
Aug. 31, 2014
Successor [Member]
Interest rate contracts [Member]
Aug. 31, 2014
Successor [Member]
Foreign exchange contracts [Member]
Aug. 31, 2013
Successor [Member]
Foreign exchange contracts [Member]
Aug. 31, 2013
Successor [Member]
Foreign exchange contracts [Member]
Aug. 31, 2014
Successor [Member]
Foreign exchange contracts [Member]
Aug. 31, 2014
Successor [Member]
Equity contracts [Member]
Aug. 31, 2013
Successor [Member]
Equity contracts [Member]
Aug. 31, 2013
Successor [Member]
Equity contracts [Member]
Aug. 31, 2014
Successor [Member]
Equity contracts [Member]
Aug. 31, 2014
Successor [Member]
Commodity contracts [Member]
Aug. 31, 2013
Successor [Member]
Commodity contracts [Member]
Aug. 31, 2013
Successor [Member]
Commodity contracts [Member]
Aug. 31, 2014
Successor [Member]
Commodity contracts [Member]
Aug. 31, 2014
Successor [Member]
Credit contracts [Member]
Aug. 31, 2013
Successor [Member]
Credit contracts [Member]
Aug. 31, 2013
Successor [Member]
Credit contracts [Member]
Aug. 31, 2014
Successor [Member]
Credit contracts [Member]
Feb. 28, 2013
Predecessor [Member]
Feb. 28, 2013
Predecessor [Member]
Interest rate contracts [Member]
Feb. 28, 2013
Predecessor [Member]
Foreign exchange contracts [Member]
Feb. 28, 2013
Predecessor [Member]
Equity contracts [Member]
Feb. 28, 2013
Predecessor [Member]
Commodity contracts [Member]
Feb. 28, 2013
Predecessor [Member]
Credit contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]                                                            
Unrealized and realized gains (losses) $ (52,849) $ 165,933 $ 238,527 $ (243,185) $ (3,803) $ 130,178 $ 177,796 $ (46,376) $ 6,697 $ (3,930) $ (25) $ 8,294 $ (49,422) $ 25,509 $ 37,588 $ (220,774) $ (4,991) $ 15,080 $ 36,593 $ 32,989 $ (1,330) $ (904) $ (13,425) $ (17,318) $ 52,864 $ 45,875 $ 12,228 $ (20,938) $ 19,585 $ (3,886)