Earnings per Share (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Basic earnings:
Net income attributable to common stockholders	$ 3,677	$ 7,839	$ 7,459	$ 5,528
Diluted earnings:
Net income attributable to common stockholders	3,677	7,839	7,459	5,528
Add: net income attributable to noncontrolling interests	26	61	51	38
Net income attributable to common stockholders and participating securities	$ 3,703	$ 7,900	$ 7,510	$ 5,566
Weighted average common shares outstanding:
Basic	64,518	38,479	58,461	33,514
Incremental shares from assumed conversion-OP units	435	436	435	436
Diluted	64,953	38,915	58,896	33,950
Basic net income per share	$ 0.06	$ 0.20	$ 0.13	$ 0.16
Diluted net income per share	$ 0.06	$ 0.20	$ 0.13	$ 0.16