NET 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
Net Earnings (Numerator) [Abstract]
Basic EPS - Net earnings	$ 11,582	$ 9,972	$ 22,470	$ 19,240
Diluted EPS - Net earnings	$ 11,582	$ 9,972	$ 22,470	$ 19,240
Number of Shares (Denominator) [Abstract]
Basic EPS - Weighted average common shares outstanding (in shares)	29,505,151	28,956,523	29,410,802	28,940,875
Effect of dilutive securities - stock options and restricted stock (in shares)	1,280,234	1,316,409	1,289,759	1,354,177
Diluted EPS - Weighted average common shares outstanding and effect of stock options and restricted stock (in shares)	30,785,385	30,272,932	30,700,561	30,295,052
Per Share Amount [Abstract]
Basic EPS - Net earnings (in dollars per share)	$ 0.39	$ 0.34	$ 0.76	$ 0.66
Diluted EPS - Net earnings (in dollars per share)	$ 0.38	$ 0.33	$ 0.73	$ 0.64
Stock Options [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive stock options outstanding, excluded from diluted earnings per share calculation (in shares)			161,286	519,455