NET INCOME PER SHARE (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
NET INCOME PER SHARE
Net income	$ 4,235	$ 11,266	$ 11,014	$ 18,462
Less: amounts allocated to nonvested shares	(43)	(135)	(111)	(221)
Basic net income available to common stockholders	4,192	11,131	10,903	18,241
Computation of basic and diluted net income per share
Add back: amounts allocated to nonvested shares	43	135	111	221
Less: amounts re-allocated to nonvested shares	(43)	(135)	(111)	(221)
Diluted net income available to common stockholders	$ 4,192	$ 11,131	$ 10,903	$ 18,241
Weighted Average Common Shares Outstanding (Denominator)
Weighted Average Common Shares Outstanding Basic	35,684,000	35,438,000	35,738,000	35,505,000
Weighted Average Common Shares Outstanding Diluted	36,497,000	36,344,000	36,634,000	36,427,000
Per Share Amount
Basic net income available to common stockholders (in dollars per share)	$ 0.12	$ 0.31	$ 0.31	$ 0.51
Diluted net income available to common stockholders (in dollars per share)	$ 0.11	$ 0.31	$ 0.30	$ 0.50
Antidilutive securities excluded from computation of diluted net income per share
Weighted-average outstanding stock options that were anti-dilutive (in Shares)	2,300,000	3,100,000	2,400,000	3,100,000
Stock options
Weighted Average Common Shares Outstanding (Denominator)
Effect on weighted average common shares outstanding from dilutive securities	813,000	906,000	896,000	922,000