THE SEPERATION AND REIT CONVERSION MERGER (Details) (USD $) In Thousands, except Share data, unless otherwise specified	0 Months Ended
	Nov. 15, 2010 note Facilities	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Nov. 14, 2010
THE SEPARATION AND REIT CONVERSION MERGER [Abstract]
Number of Real Estate Properties	86
Mortgage Loans on Real Estate, Number of Loans	26
Assets:
Real estate investments, net of accumulated depreciation		$ 827,135	$ 653,377		$ 485,337
Cash and cash equivalents	0	17,101	42,250	74,233	67,134
Restricted cash		4,589	6,093		5,527
Deferred tax assets		24,212	25,540		26,542
Prepaid expenses, deferred financing costs and other assets		29,613	17,147		11,383
Total assets		916,882	749,650		595,923
Liabilities:
Mortgage notes payable		152,322	153,942		151,678
Senior unsecured notes payable		330,666	225,000		225,000
Accounts payable and accrued liabilities		11,694	14,110		15,754
Tax liability		24,212	25,540		26,300
Total liabilities		611,394	423,077		418,732
Stockholders’ equity:
Preferred stock		0	0		0
Common stock		371	369		251
Additional paid-in capital		353,861	344,995		176,940
Total stockholders' equity	177,191	305,488	326,573		177,191
Total liabilities and stockholders’ equity		916,882	749,650		595,923
Parenthetical Information
Accumulated depreciation		$ 129,479	$ 107,331		$ 85,567
Preferred stock, par value		$ 0.01	$ 0.01		$ 0.01
Preferred stock, shares authorized		10,000,000	10,000,000		10,000,000
Preferred stock, shares issued		0	0		0
Preferred stock, shares outstanding		0	0		0
Common stock, par value		$ 0.01	$ 0.01		$ 0.01
Common stock, shares authorized		125,000,000	125,000,000		125,000,000
Common stock, shares issued		37,099,202	36,891,712		25,061,072
Common stock, shares outstanding		37,099,202	36,891,712		25,061,072