SUMMARIZED CONDENSED CONSOLIDATING INFORMATION (Condensed Consolidating Balance Sheet) (Details) (USD $) In Thousands, except Share data, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011	Sep. 30, 2011	Dec. 31, 2010
Assets
Real estate investments, net of accumulated depreciation	$ 733,054	$ 658,377
Loans receivable, net	22,092	0
Cash and cash equivalents	30,477	42,250	56,417	74,233
Restricted cash	5,197	6,093
Deferred tax assets	25,540	25,540
Prepaid expenses, deferred financing costs and other assets	26,651	17,390
Intercompany	0	0
Investments in subsidiaries	0	0
Total assets	843,011	749,650
Liabilities and stockholders’ equity
Mortgage notes payable	157,513	158,398
Senior unsecured notes payable	330,861	225,000
Accounts payable and accrued liabilities	17,778	14,139
Tax liability	25,540	25,540
Intercompany	0	0
Total liabilities	531,692	423,077
Stockholders’ equity
Preferred stock	0	0
Common stock	371	369
Additional paid-in capital	351,106	344,995
Cumulative distributions in excess of net income	(40,158)	(18,791)
Total stockholders’ equity	311,319	326,573	329,924	177,533
Total liabilities and stockholders’ equity	843,011	749,650
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	125,000,000	125,000,000
Common stock, shares issued	37,051,242	36,891,712
Common stock, shares outstanding	37,051,242	36,891,712
Parent Company [Member]
Assets
Real estate investments, net of accumulated depreciation	156	187
Loans receivable, net	0
Cash and cash equivalents	27,791	41,736	56,123	70,841
Restricted cash	0	0
Deferred tax assets	25,540	25,540
Prepaid expenses, deferred financing costs and other assets	671	874
Intercompany	0	0
Investments in subsidiaries	341,804	313,181
Total assets	395,962	381,518
Liabilities and stockholders’ equity
Mortgage notes payable	0	0
Senior unsecured notes payable	0	0
Accounts payable and accrued liabilities	4,483	6,296
Tax liability	25,540	25,540
Intercompany	54,620	23,109
Total liabilities	84,643	54,945
Stockholders’ equity
Preferred stock	0	0
Common stock	371	369
Additional paid-in capital	351,106	344,995
Cumulative distributions in excess of net income	(40,158)	(18,791)
Total stockholders’ equity	311,319	326,573
Total liabilities and stockholders’ equity	395,962	381,518
Issuers [Member]
Assets
Real estate investments, net of accumulated depreciation	0	0
Loans receivable, net	0
Cash and cash equivalents	0	0	0	0
Restricted cash	0	0
Deferred tax assets	0	0
Prepaid expenses, deferred financing costs and other assets	7,487	5,079
Intercompany	240,816	145,018
Investments in subsidiaries	435,430	391,131
Total assets	683,733	541,228
Liabilities and stockholders’ equity
Mortgage notes payable	0	0
Senior unsecured notes payable	330,861	225,000
Accounts payable and accrued liabilities	11,068	3,047
Tax liability	0	0
Intercompany	0	0
Total liabilities	341,929	228,047
Stockholders’ equity
Preferred stock	0	0
Common stock	0	0
Additional paid-in capital	291,163	288,665
Cumulative distributions in excess of net income	50,641	24,516
Total stockholders’ equity	341,804	313,181
Total liabilities and stockholders’ equity	683,733	541,228
Combined Guarantor Subsidiaries [Member]
Assets
Real estate investments, net of accumulated depreciation	555,105	474,256
Loans receivable, net	22,092
Cash and cash equivalents	0	0	0	0
Restricted cash	0	0
Deferred tax assets	0	0
Prepaid expenses, deferred financing costs and other assets	15,057	8,544
Intercompany	0	0
Investments in subsidiaries	25,119	23,611
Total assets	617,373	506,411
Liabilities and stockholders’ equity
Mortgage notes payable	0	0
Senior unsecured notes payable	0	0
Accounts payable and accrued liabilities	1,524	4,107
Tax liability	0	0
Intercompany	220,723	147,146
Total liabilities	222,247	151,253
Stockholders’ equity
Preferred stock	0	0
Common stock	0	0
Additional paid-in capital	319,390	316,011
Cumulative distributions in excess of net income	75,736	39,147
Total stockholders’ equity	395,126	355,158
Total liabilities and stockholders’ equity	617,373	506,411
Combined Non-Guarantor Subsidiaries [Member]
Assets
Real estate investments, net of accumulated depreciation	177,793	183,934
Loans receivable, net	0
Cash and cash equivalents	2,686	514	294	3,392
Restricted cash	5,197	6,093
Deferred tax assets	0	0
Prepaid expenses, deferred financing costs and other assets	3,436	2,893
Intercompany	34,527	25,237
Investments in subsidiaries	0	0
Total assets	223,639	218,671
Liabilities and stockholders’ equity
Mortgage notes payable	157,513	158,398
Senior unsecured notes payable	0	0
Accounts payable and accrued liabilities	703	689
Tax liability	0	0
Intercompany	0	0
Total liabilities	158,216	159,087
Stockholders’ equity
Preferred stock	0	0
Common stock	0	0
Additional paid-in capital	52,642	52,110
Cumulative distributions in excess of net income	12,781	7,474
Total stockholders’ equity	65,423	59,584
Total liabilities and stockholders’ equity	223,639	218,671
Elimination [Member]
Assets
Real estate investments, net of accumulated depreciation	0	0
Loans receivable, net	0
Cash and cash equivalents	0	0	0	0
Restricted cash	0	0
Deferred tax assets	0	0
Prepaid expenses, deferred financing costs and other assets	0	0
Intercompany	(275,343)	(170,255)
Investments in subsidiaries	(802,353)	(727,923)
Total assets	(1,077,696)	(898,178)
Liabilities and stockholders’ equity
Mortgage notes payable	0	0
Senior unsecured notes payable	0	0
Accounts payable and accrued liabilities	0	0
Tax liability	0	0
Intercompany	(275,343)	(170,255)
Total liabilities	(275,343)	(170,255)
Stockholders’ equity
Preferred stock	0	0
Common stock	0	0
Additional paid-in capital	(663,195)	(656,786)
Cumulative distributions in excess of net income	(139,158)	(71,137)
Total stockholders’ equity	(802,353)	(727,923)
Total liabilities and stockholders’ equity	$ (1,077,696)	$ (898,178)