STOCK-BASED COMPENSATION (Detail Textuals) (USD $)	6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012 Stock Options	Jun. 30, 2011 Stock Options	Jun. 30, 2012 Restricted Stock	Jun. 30, 2011 Restricted Stock	Jun. 30, 2012 2004 Stock Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares available for grants							2,019,000
Reserved shares of common stock							11,390,625
Term of reserved shares							10 years
Total intrinsic value of stock options exercised			$ 1,128,000	$ 10,843,000
Tax benefits related to non-qualified stock options exercised				799,000
Total fair value of shares vested					10,695,000	11,861,000
Tax benefits for compensation expense for restricted stock	2,172,000	3,419,000			2,172,000	3,419,000
Unrecognized compensation cost related to non-vested restricted shares					$ 35,114,000
Weighted-average period					3.8 years