STOCKHOLDERS' EQUITY AND SHARE-BASED COMPENSATION (Details 3) (USD $)	12 Months Ended
	Dec. 31, 2012
Options outstanding
Number (in shares)	3,058,309
Options exercisable
Number (in shares)	2,235,923
$0.00 - $10.00
Stock options outstanding and exercisable
Exercise price, low end of range (in dollars per share)	$ 0.00
Exercise price, high end of range (in dollars per share)	$ 10.00
Options outstanding
Number (in shares)	1,901,386
Weighted average remaining contractual life	5 years 5 months 5 days
Weighted average exercise price (in dollars per share)	$ 9.13
Options exercisable
Number (in shares)	1,771,805
Weighted average remaining contractual life	5 years 5 months 1 day
Weighted average exercise price (in dollars per share)	$ 9.13
$10.01 - $20.00
Stock options outstanding and exercisable
Exercise price, low end of range (in dollars per share)	$ 10.01
Exercise price, high end of range (in dollars per share)	$ 20.00
Options outstanding
Number (in shares)	187,912
Weighted average remaining contractual life	3 years 6 months 18 days
Weighted average exercise price (in dollars per share)	$ 12.50
Options exercisable
Number (in shares)	177,912
Weighted average remaining contractual life	3 years 4 months 13 days
Weighted average exercise price (in dollars per share)	$ 12.44
$20.01 - $30.00
Stock options outstanding and exercisable
Exercise price, low end of range (in dollars per share)	$ 20.01
Exercise price, high end of range (in dollars per share)	$ 30.00
Options outstanding
Number (in shares)	611,561
Weighted average remaining contractual life	7 years 3 months 14 days
Weighted average exercise price (in dollars per share)	$ 22.94
Options exercisable
Number (in shares)	247,814
Weighted average remaining contractual life	7 years 3 months 11 days
Weighted average exercise price (in dollars per share)	$ 22.87
$30.01 - $40.00
Stock options outstanding and exercisable
Exercise price, low end of range (in dollars per share)	$ 30.01
Exercise price, high end of range (in dollars per share)	$ 40.00
Options outstanding
Number (in shares)	108,950
Weighted average remaining contractual life	8 years 6 months 14 days
Weighted average exercise price (in dollars per share)	$ 34.16
Options exercisable
Number (in shares)	17,329
Weighted average remaining contractual life	8 years 6 months 11 days
Weighted average exercise price (in dollars per share)	$ 33.48
$50.01 - $60.00
Stock options outstanding and exercisable
Exercise price, low end of range (in dollars per share)	$ 50.01
Exercise price, high end of range (in dollars per share)	$ 60.00
Options outstanding
Number (in shares)	10,000
Weighted average remaining contractual life	9 years 4 months 13 days
Weighted average exercise price (in dollars per share)	$ 53.15
Options exercisable
Number (in shares)	1,250
Weighted average remaining contractual life	9 years 4 months 13 days
Weighted average exercise price (in dollars per share)	$ 53.00
$60.01 - $70.00
Stock options outstanding and exercisable
Exercise price, low end of range (in dollars per share)	$ 60.01
Exercise price, high end of range (in dollars per share)	$ 70.00
Options outstanding
Number (in shares)	158,500
Weighted average remaining contractual life	9 years 2 months 8 days
Weighted average exercise price (in dollars per share)	$ 60.66
Options exercisable
Number (in shares)	19,813
Weighted average remaining contractual life	9 years 2 months 8 days
Weighted average exercise price (in dollars per share)	$ 60.66
$80.01 - $90.00
Stock options outstanding and exercisable
Exercise price, low end of range (in dollars per share)	$ 80.01
Exercise price, high end of range (in dollars per share)	$ 90.00
Options outstanding
Number (in shares)	80,000
Weighted average remaining contractual life	9 years 7 months 13 days
Weighted average exercise price (in dollars per share)	$ 80.89