STOCK-BASED COMPENSATION (Details) (USD $)	3 Months Ended		6 Months Ended		1 Months Ended	3 Months Ended	6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	Apr. 30, 2014 Restricted stock units	Jun. 30, 2014 Restricted stock units	Jun. 30, 2014 Restricted stock units	Jun. 30, 2014 Restricted stock units 2013 Plan	Apr. 30, 2014 Restricted stock units 2013 Plan	Jun. 30, 2014 RSU granted in 2013 and 2014
Stock-based compensation
Shares granted during the period with approved performance criteria for 2013									742,100
Weighted average per unit grant date fair value (in dollars per share)									$ 8.36
Stock-based compensation expense recognized	$ 1,252,000	$ 1,300,000	$ (255,000)	$ 2,638,000		$ 1,000,000	$ 1,500,000
Granted (in shares)					762,963
Vesting period					4 years
Compensation cost related to unvested granted awards not yet recognized								12,400,000		4,700,000
Compensation cost related to RSU for which performance criteria for 2015 and following years are not set								$ 7,700,000
Weighted average period of recognition of unrecognized compensation cost related to nonvested awards							3 years 6 months