STOCK-BASED COMPENSATION Option Grants (Details) (Stock Options [Member], USD $)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Number of Options Granted	555,000	720,000	691,875
Risk Free Interest Rate	1.67%	2.02%	1.40%
Expected Term (years)	4.82	4.9	3.9
Expected Volatility Rate	57.90%	57.26%	57.20%
Dividend yield	0.00%	0.00%	0.00%
Fair Value (US$/share)	$ 10.98	$ 12.64	$ 8.31
Weighted Average Exercise Price (US$/share), granted	$ 22.33	$ 25.59	$ 18.68
January 3 2011 100000 [Member]
Number of Options Granted	15,000
Risk Free Interest Rate	2.11%
Expected Term (years)	5.3
Expected Volatility Rate	55.60%
Fair Value (US$/share)	$ 10.71
Weighted Average Exercise Price (US$/share), granted	$ 21.20
May 16 2011 100000 [Member]
Number of Options Granted	100,000
Risk Free Interest Rate	0.93%
Expected Term (years)	3.0
Expected Volatility Rate	67.60%
Fair Value (US$/share)	$ 10.06
Weighted Average Exercise Price (US$/share), granted	$ 22.38
May 16 2011 435000 [Member]
Number of Options Granted	435,000
Risk Free Interest Rate	1.83%
Expected Term (years)	5.3
Expected Volatility Rate	55.70%
Fair Value (US$/share)	$ 11.23
Weighted Average Exercise Price (US$/share), granted	$ 22.38
June 14 2011 5000 [Member]
Number of Options Granted	5,000
Risk Free Interest Rate	0.79%
Expected Term (years)	3.0
Expected Volatility Rate	67.50%
Fair Value (US$/share)	$ 9.01
Weighted Average Exercise Price (US$/share), granted	$ 20.11