STOCK-BASED COMPENSATION Exercise Price Range (Details) (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2011 years
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Shares, options outstanding	2,901,687
Averaged remaining contractual life (years), options outstanding	4.49
Aggregate intrinsic value (US$), options outstanding	$ 71,427
Weighted average exercise price (US$), options outstanding	$ 32.86
Shares, options exercisable	1,829,813
Average remaining contractual life (years), options exercisable	3.33
Aggregate intrinsic value (US$), options exercisable	71,427
Weighted average exercise price (US$), options exercisable	$ 38.27
Range 1 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Shares, options outstanding	603,938
Averaged remaining contractual life (years), options outstanding	2.63
Aggregate intrinsic value (US$), options outstanding	71,427
Weighted average exercise price (US$), options outstanding	$ 17.30
Shares, options exercisable	603,938
Average remaining contractual life (years), options exercisable	2.63
Aggregate intrinsic value (US$), options exercisable	71,427
Weighted average exercise price (US$), options exercisable	$ 17.30
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Upper Range Limit	$ 20.00
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Lower Range Limit	$ 0.01
Range 2 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Shares, options outstanding	1,719,374
Averaged remaining contractual life (years), options outstanding	5.64
Aggregate intrinsic value (US$), options outstanding	0
Weighted average exercise price (US$), options outstanding	$ 23.77
Shares, options exercisable	647,500
Average remaining contractual life (years), options exercisable	4.27
Aggregate intrinsic value (US$), options exercisable	0
Weighted average exercise price (US$), options exercisable	$ 24.04
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Upper Range Limit	$ 40.00
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Lower Range Limit	$ 20.01
Range 3 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Shares, options outstanding	197,125
Averaged remaining contractual life (years), options outstanding	3.75
Aggregate intrinsic value (US$), options outstanding	0
Weighted average exercise price (US$), options outstanding	$ 51.93
Shares, options exercisable	197,125
Average remaining contractual life (years), options exercisable	3.75
Aggregate intrinsic value (US$), options exercisable	0
Weighted average exercise price (US$), options exercisable	$ 51.93
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Upper Range Limit	$ 60.00
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Lower Range Limit	$ 40.01
Range 4 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Shares, options outstanding	183,000
Averaged remaining contractual life (years), options outstanding	2.44
Aggregate intrinsic value (US$), options outstanding	0
Weighted average exercise price (US$), options outstanding	$ 66.73
Shares, options exercisable	183,000
Average remaining contractual life (years), options exercisable	2.48
Aggregate intrinsic value (US$), options exercisable	0
Weighted average exercise price (US$), options exercisable	$ 66.73
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Upper Range Limit	$ 80.00
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Lower Range Limit	$ 60.01
Range 5 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Shares, options outstanding	30,000
Averaged remaining contractual life (years), options outstanding	0.43
Aggregate intrinsic value (US$), options outstanding	0
Weighted average exercise price (US$), options outstanding	$ 90.54
Shares, options exercisable	30,000
Average remaining contractual life (years), options exercisable	0.43
Aggregate intrinsic value (US$), options exercisable	0
Weighted average exercise price (US$), options exercisable	$ 90.54
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Upper Range Limit	$ 100.00
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Lower Range Limit	$ 80.01
Range 6 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Shares, options outstanding	168,250
Averaged remaining contractual life (years), options outstanding	3.19
Aggregate intrinsic value (US$), options outstanding	0
Weighted average exercise price (US$), options outstanding	$ 112.07
Shares, options exercisable	168,250
Average remaining contractual life (years), options exercisable	3.19
Aggregate intrinsic value (US$), options exercisable	$ 0
Weighted average exercise price (US$), options exercisable	$ 112.07
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Upper Range Limit	$ 120.00
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Lower Range Limit	$ 100.01