Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Investment in real estate:
Land	$ 1,065,368	$ 1,025,246
Land improvements	2,685,613	2,667,213
Buildings and other depreciable property	545,148	535,647
Real Estate Investment Property, at Cost, Total	4,296,129	4,228,106
Accumulated depreciation	(1,087,380)	(1,058,540)
Net investment in real estate	3,208,749	3,169,566
Cash	56,427	58,427
Notes receivable, net	38,610	42,990
Investment in joint ventures	14,477	11,583
Deferred financing costs, net	18,984	19,873
Deferred commission expense	25,806	25,251
Escrow deposits and other assets	47,509	63,949
Total Assets	3,410,562	3,391,639
Liabilities:
Mortgage notes payable	1,976,426	1,992,368
Term loan	200,000	200,000
Unsecured lines of credit	0	0
Accrued payroll and other operating expenses	72,585	65,157
Deferred revenue - upfront payments from right-to-use contracts	69,820	68,673
Deferred revenue - right-to-use annual payments	15,341	11,136
Accrued interest payable	9,712	9,416
Rents and other customer payments received in advance and security deposits	62,466	58,931
Distributions payable	29,478	22,753
Total Liabilities	2,435,828	2,428,434
Stockholders' Equity:
Preferred stock value	0	0
Common stock, $0.01 par value	834	834
Paid-in capital	1,020,925	1,021,365
Distributions in excess of accumulated earnings	253,065	264,083
Accumulated other comprehensive loss	(482)	(927)
Total Stockholders’ Equity	904,356	893,333
Non-controlling interests - Common OP Units	70,378	69,872
Total Equity	974,734	963,205
Total Liabilities and Equity	3,410,562	3,391,639
Cumulative Series C Six Point Seven Five Percent Redeemable Perpetual Preferred Stock [Domain]
Stockholders' Equity:
Preferred stock value	$ 136,144	$ 136,144