Fair Value Measurements (Details) (Fair value measurement, recurring basis [Member], USD $)	Dec. 31, 2013	Jan. 31, 2013
Financial assets and liabilities and redeemable noncontrolling interests on a recurring basis
Fair value adjustment to the borrowings subject to TRS	$ 8,869,000	$ 9,950,000
Redeemable noncontrolling interest	(171,743,000)	(239,136,000)
Fair value of financial assets and liabilities and redeemable noncontrolling interests on a recurring basis	(284,923,000)	(363,596,000)
Interest rate caps [Member]
Financial assets and liabilities and redeemable noncontrolling interests on a recurring basis
Derivative assets	155,000	7,000
Interest rate swap agreements [Member]
Financial assets and liabilities and redeemable noncontrolling interests on a recurring basis
Derivative assets		241,000
Derivative liabilities	(97,858,000)	(129,522,000)
Total Return Swap [Member]
Financial assets and liabilities and redeemable noncontrolling interests on a recurring basis
Derivative assets	903,000	21,066,000
Derivative liabilities	(25,249,000)	(26,202,000)
Fair Value, Inputs, Level 1 [Member]
Financial assets and liabilities and redeemable noncontrolling interests on a recurring basis
Fair value adjustment to the borrowings subject to TRS	0	0
Redeemable noncontrolling interest	0	0
Fair value of financial assets and liabilities and redeemable noncontrolling interests on a recurring basis	0	0
Fair Value, Inputs, Level 1 [Member] | Interest rate caps [Member]
Financial assets and liabilities and redeemable noncontrolling interests on a recurring basis
Derivative assets	0	0
Fair Value, Inputs, Level 1 [Member] | Interest rate swap agreements [Member]
Financial assets and liabilities and redeemable noncontrolling interests on a recurring basis
Derivative assets		0
Derivative liabilities	0	0
Fair Value, Inputs, Level 1 [Member] | Total Return Swap [Member]
Financial assets and liabilities and redeemable noncontrolling interests on a recurring basis
Derivative assets	0	0
Derivative liabilities	0	0
Fair Value, Inputs, Level 2 [Member]
Financial assets and liabilities and redeemable noncontrolling interests on a recurring basis
Fair value adjustment to the borrowings subject to TRS	0	0
Redeemable noncontrolling interest	0	0
Fair value of financial assets and liabilities and redeemable noncontrolling interests on a recurring basis	(343,000)	(2,768,000)
Fair Value, Inputs, Level 2 [Member] | Interest rate caps [Member]
Financial assets and liabilities and redeemable noncontrolling interests on a recurring basis
Derivative assets	155,000	7,000
Fair Value, Inputs, Level 2 [Member] | Interest rate swap agreements [Member]
Financial assets and liabilities and redeemable noncontrolling interests on a recurring basis
Derivative assets		241,000
Derivative liabilities	(498,000)	(3,016,000)
Fair Value, Inputs, Level 2 [Member] | Total Return Swap [Member]
Financial assets and liabilities and redeemable noncontrolling interests on a recurring basis
Derivative assets	0	0
Derivative liabilities	0	0
Fair Value, Inputs, Level 3 [Member]
Financial assets and liabilities and redeemable noncontrolling interests on a recurring basis
Fair value adjustment to the borrowings subject to TRS	8,869,000	9,950,000
Redeemable noncontrolling interest	(171,743,000)	(239,136,000)
Fair value of financial assets and liabilities and redeemable noncontrolling interests on a recurring basis	(284,580,000)	(360,828,000)
Fair Value, Inputs, Level 3 [Member] | Interest rate caps [Member]
Financial assets and liabilities and redeemable noncontrolling interests on a recurring basis
Derivative assets	0	0
Fair Value, Inputs, Level 3 [Member] | Interest rate swap agreements [Member]
Financial assets and liabilities and redeemable noncontrolling interests on a recurring basis
Derivative assets		0
Derivative liabilities	(97,360,000)	(126,506,000)
Fair Value, Inputs, Level 3 [Member] | Total Return Swap [Member]
Financial assets and liabilities and redeemable noncontrolling interests on a recurring basis
Derivative assets	903,000	21,066,000
Derivative liabilities	$ (25,249,000)	$ (26,202,000)