EARNINGS PER SHARE (Basic and Diluted) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Basic, numerator:
Net income	$ 12,940	$ 19,154	$ 17,068	$ 39,866
Effect of unvested restricted stock unit awards	(89)	(175)	(132)	(418)
Adjusted net income	$ 12,851	$ 18,979	$ 16,936	$ 39,448
Basic, denominator:
Weighted-average shares	25,724,550	26,009,344	25,779,166	26,033,467
Earnings per common share (in dollars per share)	$ 0.50	$ 0.73	$ 0.66	$ 1.52
Diluted, numerator:
Net income	$ 12,940	$ 19,154	$ 17,068	$ 39,866
Effect of unvested restricted stock unit awards	(87)	(172)	(131)	(410)
Adjusted net income	$ 12,853	$ 18,982	$ 16,937	$ 39,456
Diluted, denominator:
Weighted-average shares	25,724,550	26,009,344	25,779,166	26,033,467
Effect of dilutive securities	486,974	499,138	484,566	536,333
Adjusted weighted-average shares and assumed conversions	26,211,524	26,508,482	26,263,732	26,569,800
Earnings per common share (in dollars per share)	$ 0.49	$ 0.72	$ 0.64	$ 1.48