ACQUISITIONS AND PRO FORMA RESULTS (Pro Forma Financial Information Summarization Results of Operations) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Business Combinations [Abstract]
Total revenue from continuing operations, As reported	$ 255,664	$ 250,332	$ 249,309	$ 236,770	$ 241,160	$ 226,367	$ 212,673	$ 202,534	$ 992,075	$ 882,734	$ 796,717
Total revenue from continuing operations, Pro forma										940,089	921,998
Net income from continuing operations, As reported	$ 28,246	$ 20,144	$ 12,755	$ 13,419	$ 14,980	$ (31,881)	$ 12,020	$ 11,732	$ 74,564	6,851	36,295
Net income from continuing operations, Pro forma										$ 10,749	$ 40,721
Net income from continuing operations per share:
Basic net income per common share from continuing operations (in dollars per share)	$ 0.38	$ 0.27	$ 0.17	$ 0.18	$ 0.20	$ (0.45)	$ 0.18	$ 0.18	$ 1.00	$ 0.10	$ 0.56
Basic, Pro forma (in dollars per share)										$ 0.14	$ 0.56