EARNINGS PER SHARE (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Jan. 31, 2014
EARNINGS PER SHARE OF COMMON STOCK, BASIC AND DILUTED [Line Items]
Net income	$ 39,202	$ 7,371	$ 12,076	$ 60,381	$ 36,607	$ 4,653	$ 9,454	$ 59,076	$ 119,030	$ 109,790	$ 99,195
Weighted Average Number of Shares Outstanding, Basic									52,578,000	52,364,000	52,319,000
Earnings Per Share, Basic	$ 0.75	$ 0.14	$ 0.23	$ 1.15	$ 0.70	$ 0.09	$ 0.18	$ 1.13	$ 2.26	$ 2.10	$ 1.90
Dilutive Securities, Effect on Basic Earnings Per Share									$ 0	$ 0	$ 0
Weighted Average Number Diluted Shares Outstanding Adjustment									676,000	582,000	0
Net Income (Loss) Available to Common Stockholders, Diluted									$ 119,030	$ 109,790	$ 99,195
Weighted Average Number of Shares Outstanding, Diluted									53,254,000	52,946,000	52,319,000
Earnings Per Share, Diluted	$ 0.74	$ 0.14	$ 0.23	$ 1.13	$ 0.69	$ 0.09	$ 0.18	$ 1.13	$ 2.24	$ 2.07	$ 1.90
Common Stock, Shares, Issued	52,598,005				52,083,859				52,598,005	52,083,859		51,941,236