Fair Value Measurements (Details 1) (USD $)	9 Months Ended
	Oct. 31, 2013	Oct. 31, 2012
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning	$ (360,828,000)	$ (378,285,000)
Contribution from redeemable noncontrolling interest	0	(11,348,000)
Loss attributable to redeemable noncontrolling interest	17,296,000	6,316,000
Total realized and unrealized gains (losses):
Included in earnings	(2,815,000)	10,323,000
Included in other comprehensive income	20,616,000	8,156,000
Included in additional paid-in capital	47,538,000	(6,609,000)
Balance, ending	(278,193,000)	(371,447,000)
Redeemable Noncontrolling Interest [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning	(239,136,000)	(229,149,000)
Contribution from redeemable noncontrolling interest		(11,348,000)
Loss attributable to redeemable noncontrolling interest	17,296,000	6,316,000
Total realized and unrealized gains (losses):
Included in earnings	0	0
Included in other comprehensive income	0	0
Included in additional paid-in capital	47,538,000	(6,609,000)
Balance, ending	(174,302,000)	(240,790,000)
Interest Rate Swaps [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning	(126,506,000)	(143,303,000)
Contribution from redeemable noncontrolling interest		0
Loss attributable to redeemable noncontrolling interest	0	0
Total realized and unrealized gains (losses):
Included in earnings	0	0
Included in other comprehensive income	20,616,000	8,156,000
Included in additional paid-in capital	0	0
Balance, ending	(105,890,000)	(135,147,000)
Net TRS [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning	(5,136,000)	(15,013,000)
Contribution from redeemable noncontrolling interest		0
Loss attributable to redeemable noncontrolling interest	0	0
Total realized and unrealized gains (losses):
Included in earnings	275,000	9,805,000
Included in other comprehensive income	0	0
Included in additional paid-in capital	0	0
Balance, ending	(4,861,000)	(5,208,000)
Fair Value Adjustment to the Borrowings Subject to TRS [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning	9,950,000	9,180,000
Contribution from redeemable noncontrolling interest		0
Loss attributable to redeemable noncontrolling interest	0	0
Total realized and unrealized gains (losses):
Included in earnings	(3,090,000)	518,000
Included in other comprehensive income	0	0
Included in additional paid-in capital	0	0
Balance, ending	6,860,000	9,698,000
TRS Related [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning	4,814,000	(5,833,000)
Contribution from redeemable noncontrolling interest		0
Loss attributable to redeemable noncontrolling interest	0	0
Total realized and unrealized gains (losses):
Included in earnings	(2,815,000)	10,323,000
Included in other comprehensive income	0	0
Included in additional paid-in capital	0	0
Balance, ending	$ 1,999,000	$ 4,490,000