Equity, Capital and other Interests (Details 1) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended	6 Months Ended	12 Months Ended
	Mar. 31, 2011	Jun. 30, 2011	Dec. 31, 2010
Preferred shares schedule
Preferred stock value		$ 200,000	$ 200,000
Shares issued		1,600,000	1,600,000
Shares outstanding		1,600,000	1,600,000
OPERATING PARTNERSHIP | 8.29% Series K Cumulative Redeemable Preferred [Member]
Preferred shares schedule
Redemption Date		Dec. 10, 2026
Annual dividend per preferred share/preference unit		$ 4.145
Preferred units value		50,000	50,000
8.29% Series K Cumulative Redeemable Preferred [Member]
Preferred shares schedule
Redemption Date		Dec. 10, 2026
Annual dividend per preferred share/preference unit		$ 4.145
Preferred stock value		50,000	50,000
Annual dividend rate	8.29%	8.29%	8.29%
Liquidation value per share	$ 50	$ 50	$ 50
Shares issued	1,000,000	1,000,000	1,000,000
Shares outstanding	1,000,000	1,000,000	1,000,000
OPERATING PARTNERSHIP | 6.48% Series N Cumulative Redeemable Preferred [Member]
Preferred shares schedule
Redemption Date		Jun. 19, 2008
Annual dividend per preferred share/preference unit		$ 16.20
Preferred units value		150,000	150,000
6.48% Series N Cumulative Redeemable Preferred [Member]
Preferred shares schedule
Redemption Date		Jun. 19, 2008
Annual dividend per preferred share/preference unit		$ 16.20
Preferred stock value		150,000	150,000
Annual dividend rate	6.48%	6.48%	6.48%
Liquidation value per share	$ 250	$ 250	$ 250
Shares issued	600,000	600,000	600,000
Shares outstanding	600,000	600,000	600,000
OPERATING PARTNERSHIP
Preferred shares schedule
Preferred units value		$ 200,000	$ 200,000