Consolidated Statements of Equity (Unaudited) (USD $) In Thousands, except Share data	Total	Common Shares [Member]	Additional Paid-in Capital [Member]	Accumulated Dividends in excess of net income [Member]	Noncontrolling Interests - Unitholders in the Operating Partnership [Member]
Beginning balance at Dec. 31, 2011	$ 679,728	$ 393	$ 653,645	$ (28,007)	$ 53,697
Beginning balance, shares at Dec. 31, 2011	39,283,796	39,283,796
Net income	9,780			6,758	3,022
Conversion of operating partnership units, Shares		24,903
Conversion of operating partnership units			652		(652)
Issuance of restricted stock, Shares		10,015
Forfeiture of restricted stock, Shares		(2,253)
Dividends declared and paid	(36,339)			(24,755)	(11,584)
Stock-based compensation	2,128		2,128
Ending balance at Sep. 30, 2012	$ 655,297	$ 393	$ 656,425	$ (46,004)	$ 44,483
Ending balance, shares at Sep. 30, 2012	39,316,461	39,316,461