EARNINGS PER COMMON SHARE (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended															12 Months Ended
	Dec. 31, 2013		Sep. 30, 2013	Jun. 30, 2013		Mar. 31, 2013		Dec. 31, 2012		Sep. 30, 2012		Jun. 30, 2012		Mar. 31, 2012		Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Basic and Diluted Earnings per Share [Line Items]
Net income	$ 26,526		$ 11,725	$ 15,496		$ 22,393		$ (2,418)		$ 8,730		$ 14,716		$ 19,184		$ 76,140		$ 40,212		$ 11
Weighted-average common shares outstanding																25,325,695		25,447,918		25,878,535
Weighted-average common shares, Diluted																25,531,375		25,504,526		25,958,849
Basic earnings per common share (in usd per share)	$ 1.04	[1]	$ 0.46	$ 0.61	[1]	$ 0.89	[1]	$ (0.10)	[1]	$ 0.34	[1]	$ 0.58	[1]	$ 0.75	[1]	$ 3.01		$ 1.58	[1]	$ 0.00
Diluted earnings per common share (in usd per share)	$ 1.04	[1]	$ 0.45	$ 0.61	[1]	$ 0.88	[1]	$ (0.10)	[1]	$ 0.34	[1]	$ 0.58	[1]	$ 0.75	[1]	$ 2.98		$ 1.58	[1]	$ 0.00
Awards excluded from diluted calculation																638,478	[2]	901,008	[2]	989,047	[2]
Restricted Stock Awards [Member]
Basic and Diluted Earnings per Share [Line Items]
Add dilutive effect of share-based awards outstanding																59,849		54,338		50,206
Stock Options [Member]
Basic and Diluted Earnings per Share [Line Items]
Add dilutive effect of share-based awards outstanding																145,831		2,270		30,108

[1] The sum of the quarterly reported amounts may not equal the full year, as each is computed independently.

[2] Outstanding awards that are not “in-the-money” are excluded from the diluted earnings per share calculation because the effect of including them would have been anti-dilutive.