EARNINGS PER SHARE (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Basic and diluted net earnings per share
Net earnings applicable to common shareholders	$ 9,183	$ 5,257	$ 12,008	$ 9,065
Weighted average shares outstanding - basic	72,283,896	71,062,658	72,138,686	71,043,874
Effect of dilutive securities - restricted stock	11,822		15,592
Effect of dilutive securities - stock options	557,159	895,656	569,175	1,050,449
Weighted average shares outstanding - diluted	72,852,877	71,958,314	72,723,453	72,094,323
Basic net earnings per share (in dollars per share)	$ 0.13	$ 0.07	$ 0.17	$ 0.13
Diluted net earnings per share (in dollars per share)	$ 0.13	$ 0.07	$ 0.17	$ 0.13
Convertible bonds and preferred stock
Earnings per share
Anti-dilutive securities (in shares)			38,072	52,093
Stock options and restricted stock
Earnings per share
Anti-dilutive securities (in shares)			2,794,021	1,705,448
Convertible debentures
Earnings per share
Percentage of principal amount at which debentures may be converted from the date of issuance until maturity into common stock			100.00%
Conversion price (in dollars per share)	$ 50		$ 50
Stock options
Earnings per share
Weighted average exercise price (in dollars per share)	$ 2.22	$ 2.90	$ 2.22	$ 2.90