EARNINGS 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
Basic and diluted net earnings per share
Net earnings applicable to common shareholders	$ 14,656	$ 2,405	$ 26,664	$ 11,469
Weighted average shares outstanding - basic	72,424,626	71,178,903	72,235,047	71,089,212
Effect of dilutive securities - restricted stock	0		0
Effect of dilutive securities - stock options	194,107	861,490	190,803	937,933
Weighted average shares outstanding - diluted	72,618,733	72,040,393	72,425,850	72,027,145
Basic net earnings per share (in dollars per share)	$ 0.20	$ 0.03	$ 0.37	$ 0.16
Diluted net earnings per share (in dollars per share)	$ 0.20	$ 0.03	$ 0.37	$ 0.16
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)			2,910,907	1,644,817
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)	$ 2.59	$ 2.88	$ 2.59	$ 2.88