CALCULATION OF WEIGHTED AVERAGE SHARES OUTSTANDING FOR EARNINGS PER SHARE (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Earnings Per Share [Abstract]
Net income	$ 12,947	$ 14,819	$ 38,329	$ 42,356	$ 54,070
Basic weighted average shares outstanding	20,755	19,373	20,418	19,353
Plus unvested restricted stock	66	47	50	33
Diluted weighted shares outstanding	20,821	19,420	20,468	19,386
Earnings per common share
Basic (in dollars per share)	$ 0.62	$ 0.76	$ 1.88	$ 2.19
Diluted (in dollars per share)	$ 0.62	$ 0.76	$ 1.87	$ 2.18