EARNINGS PER SHARE (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Basic, numerator:
Net income	$ 19,618	$ 13,982	$ 31,633	$ 5,465
Effect of unvested restricted stock unit awards	(981)	(585)	(1,591)	(243)
Adjusted net income	18,637	13,397	30,042	5,222
Basic, denominator:
Weighted-average shares	26,054,678	25,736,810	25,979,555	25,690,184
Earnings per common share (in dollars per share)	$ 0.72	$ 0.52	$ 1.16	$ 0.20
Diluted, numerator:
Net income	19,618	13,982	31,633	5,465
Effect of unvested restricted stock unit awards	(981)	(585)	(1,591)	(243)
Adjusted net income	$ 18,637	$ 13,397	$ 30,042	$ 5,222
Diluted, denominator:
Weighted-average shares	26,054,678	25,736,810	25,979,555	25,690,184
Effect of dilutive securities			453
Adjusted weighted-average shares and assumed conversions	26,054,678	25,736,810	25,980,008	25,690,184
Earnings per common share (in dollars per share)	$ 0.72	$ 0.52	$ 1.16	$ 0.20