Fair Value Measurements (Details) (USD $) In Thousands	Jul. 31, 2011
Fair Value Assets Measured on Recurring Basis
Fair value adjustment to the borrowings subject to TRS	$ 13,571
Fair Value Liabilities Measured on Recurring Basis
Redeemable noncontrolling interest	(226,936)
Total	(360,562)
Fair Value, Inputs, Level 1 [Member]
Fair Value Assets Measured on Recurring Basis
Fair value adjustment to the borrowings subject to TRS	0
Fair Value, Inputs, Level 1 [Member] | Interest Rate Cap [Member]
Fair Value Assets Measured on Recurring Basis
Fair value assets measured on recurring basis	0
Fair Value, Inputs, Level 1 [Member] | Interest rate swap agreements [Member]
Fair Value Assets Measured on Recurring Basis
Fair value assets measured on recurring basis	0
Fair Value, Inputs, Level 1 [Member] | Total Return Swap [Member]
Fair Value Assets Measured on Recurring Basis
Fair value assets measured on recurring basis	0
Fair Value, Inputs, Level 1 [Member]
Fair Value Liabilities Measured on Recurring Basis
Redeemable noncontrolling interest	0
Total	0
Fair Value, Inputs, Level 1 [Member] | Interest rate swap agreements [Member]
Fair Value Liabilities Measured on Recurring Basis
Fair Value Liabilities Measured on Recurring Basis	0
Fair Value, Inputs, Level 1 [Member] | Total Return Swap [Member]
Fair Value Liabilities Measured on Recurring Basis
Fair Value Liabilities Measured on Recurring Basis	0
Fair Value, Inputs, Level 2 [Member]
Fair Value Assets Measured on Recurring Basis
Fair value adjustment to the borrowings subject to TRS	0
Fair Value, Inputs, Level 2 [Member] | Interest Rate Cap [Member]
Fair Value Assets Measured on Recurring Basis
Fair value assets measured on recurring basis	40
Fair Value, Inputs, Level 2 [Member] | Interest rate swap agreements [Member]
Fair Value Assets Measured on Recurring Basis
Fair value assets measured on recurring basis	1,523
Fair Value, Inputs, Level 2 [Member] | Total Return Swap [Member]
Fair Value Assets Measured on Recurring Basis
Fair value assets measured on recurring basis	0
Fair Value, Inputs, Level 2 [Member]
Fair Value Liabilities Measured on Recurring Basis
Redeemable noncontrolling interest	0
Total	(5,525)
Fair Value, Inputs, Level 2 [Member] | Interest rate swap agreements [Member]
Fair Value Liabilities Measured on Recurring Basis
Fair Value Liabilities Measured on Recurring Basis	(7,088)
Fair Value, Inputs, Level 2 [Member] | Total Return Swap [Member]
Fair Value Liabilities Measured on Recurring Basis
Fair Value Liabilities Measured on Recurring Basis	0
Fair Value, Inputs, Level 3 [Member]
Fair Value Assets Measured on Recurring Basis
Fair value adjustment to the borrowings subject to TRS	13,571
Fair Value, Inputs, Level 3 [Member] | Interest Rate Cap [Member]
Fair Value Assets Measured on Recurring Basis
Fair value assets measured on recurring basis	0
Fair Value, Inputs, Level 3 [Member] | Interest rate swap agreements [Member]
Fair Value Assets Measured on Recurring Basis
Fair value assets measured on recurring basis	0
Fair Value, Inputs, Level 3 [Member] | Total Return Swap [Member]
Fair Value Assets Measured on Recurring Basis
Fair value assets measured on recurring basis	3,839
Fair Value, Inputs, Level 3 [Member]
Fair Value Liabilities Measured on Recurring Basis
Redeemable noncontrolling interest	(226,936)
Total	(355,037)
Fair Value, Inputs, Level 3 [Member] | Interest rate swap agreements [Member]
Fair Value Liabilities Measured on Recurring Basis
Fair Value Liabilities Measured on Recurring Basis	(121,459)
Fair Value, Inputs, Level 3 [Member] | Total Return Swap [Member]
Fair Value Liabilities Measured on Recurring Basis
Fair Value Liabilities Measured on Recurring Basis	(24,052)
Interest Rate Cap [Member]
Fair Value Assets Measured on Recurring Basis
Fair value assets measured on recurring basis	40
Interest rate swap agreements [Member]
Fair Value Assets Measured on Recurring Basis
Fair value assets measured on recurring basis	1,523
Fair Value Liabilities Measured on Recurring Basis
Fair Value Liabilities Measured on Recurring Basis	(128,547)
Total Return Swap [Member]
Fair Value Assets Measured on Recurring Basis
Fair value assets measured on recurring basis	3,839
Fair Value Liabilities Measured on Recurring Basis
Fair Value Liabilities Measured on Recurring Basis	$ (24,052)