SUMMARY OF QUARTERLY FINANCIAL INFORMATION Quarterly Financial Information Disclosure (Details) (USD $) In Thousands, except Share data, unless otherwise specified	0 Months Ended	1 Months Ended	3 Months Ended								12 Months Ended
	Nov. 29, 2011	Feb. 27, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Quarterly Financial Information Disclosure [Abstract]
Revenue			$ 37,141	$ 34,648	$ 32,723	$ 29,913	$ 28,783	$ 27,356	$ 29,206	$ 29,733	$ 134,425	$ 115,078	$ 116,390
Income from continuing operations			8,682	6,238	5,677	3,437	3,462	3,514	3,841	7,897	24,034	18,713	28,233
Income from discontinued operations attributable to Common Shareholders			12,594	1,343	1,162	573	4,425	497	26,393	1,526	15,672	32,842	1,824
Net income attributable to Common Shareholders			$ 21,276	$ 7,581	$ 6,839	$ 4,010	$ 7,887	$ 4,011	$ 30,234	$ 9,423	$ 39,706	$ 51,555	$ 30,057
Net income attributable to Common Shareholders per Common Share - basic:
Income from continuing operations (in dollars per share)			$ 0.17	$ 0.13	$ 0.13	$ 0.08	$ 0.08	$ 0.09	$ 0.09	$ 0.19	$ 0.51	$ 0.45	$ 0.69
Income from discontinued operations (in dollars per share)			$ 0.25	$ 0.03	$ 0.02	$ 0.01	$ 0.10	$ 0.01	$ 0.64	$ 0.04	$ 0.34	$ 0.80	$ 0.04
Net income per share (in dollars per share)			$ 0.42	$ 0.16	$ 0.15	$ 0.09	$ 0.18	$ 0.10	$ 0.73	$ 0.23	$ 0.85	$ 1.25	$ 0.73
Net income attributable to Common Shareholders per Common Share - diluted:
Income from continuing operations (in dollars per share)			$ 0.17	$ 0.13	$ 0.13	$ 0.08	$ 0.08	$ 0.09	$ 0.09	$ 0.19	$ 0.51	$ 0.45	$ 0.69
Income from discontinued operations (in dollars per share)			$ 0.25	$ 0.03	$ 0.02	$ 0.01	$ 0.11	$ 0.01	$ 0.64	$ 0.04	$ 0.34	$ 0.80	$ 0.04
Net income per share (in dollars per share)			$ 0.42	$ 0.16	$ 0.15	$ 0.09	$ 0.19	$ 0.10	$ 0.73	$ 0.23	$ 0.85	$ 1.25	$ 0.73
Cash dividends declared per Common Share	$ 0.18	$ 0.21	$ 0.18	$ 0.18	$ 0.18	$ 0.18	$ 0.18	$ 0.18	$ 0.18	$ 0.18	$ 0.72	$ 0.72	$ 0.72
Weighted average Common Shares outstanding:
Basic			50,046,774	46,338,218	44,245,401	42,735,731	41,785,261	40,339,958	40,333,575	40,317,603
Diluted			50,582,584	46,812,349	44,673,565	43,146,093	42,066,390	40,628,781	40,633,317	40,580,173	46,335,000	40,986,000	40,406,000