STOCK-BASED COMPENSATION - Exercise Prices (Details) shares in Thousands	12 Months Ended
	Dec. 31, 2015 $ / shares shares
Stock options outstanding and stock options exercisable
Stock options outstanding (in shares) | shares	6,590
Options Outstanding, Weighted Average Remaining Contractual Term (in years)	5 years 7 months 6 days
Options Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 50.85
Options Exercisable (in shares) | shares	3,899
Options Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 24.36
Range of Exercise Prices $13.53 - $13.53
Stock options outstanding and stock options exercisable
Stock options, range of exercise prices, low end of range (in dollars per share)	13.53
Stock options, range of exercise prices, high end of range (in dollars per share)	$ 13.53
Stock options outstanding (in shares) | shares	33
Options Outstanding, Weighted Average Remaining Contractual Term (in years)	2 years 10 months 24 days
Options Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 13.53
Options Exercisable (in shares) | shares	33
Options Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 13.53
Range of Exercise Prices $15.86 - $15.86
Stock options outstanding and stock options exercisable
Stock options, range of exercise prices, low end of range (in dollars per share)	15.86
Stock options, range of exercise prices, high end of range (in dollars per share)	$ 15.86
Stock options outstanding (in shares) | shares	1,663
Options Outstanding, Weighted Average Remaining Contractual Term (in years)	2 years 4 months 24 days
Options Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 15.86
Options Exercisable (in shares) | shares	1,663
Options Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 15.86
Range of Exercise Prices $16.84 - $16.84
Stock options outstanding and stock options exercisable
Stock options, range of exercise prices, low end of range (in dollars per share)	16.84
Stock options, range of exercise prices, high end of range (in dollars per share)	$ 16.84
Stock options outstanding (in shares) | shares	18
Options Outstanding, Weighted Average Remaining Contractual Term (in years)	3 years 1 month 6 days
Options Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 16.84
Options Exercisable (in shares) | shares	18
Options Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 16.84
Range of Exercise Prices $17.82 - $17.82
Stock options outstanding and stock options exercisable
Stock options, range of exercise prices, low end of range (in dollars per share)	17.82
Stock options, range of exercise prices, high end of range (in dollars per share)	$ 17.82
Stock options outstanding (in shares) | shares	1,147
Options Outstanding, Weighted Average Remaining Contractual Term (in years)	3 years 10 months 24 days
Options Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 17.82
Options Exercisable (in shares) | shares	1,147
Options Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 17.82
Range of Exercise Prices $18.07 - $47.13
Stock options outstanding and stock options exercisable
Stock options, range of exercise prices, low end of range (in dollars per share)	18.07
Stock options, range of exercise prices, high end of range (in dollars per share)	$ 47.13
Stock options outstanding (in shares) | shares	956
Options Outstanding, Weighted Average Remaining Contractual Term (in years)	5 years 8 months 12 days
Options Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 36.58
Options Exercisable (in shares) | shares	498
Options Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 28.06
Range of Exercise Prices $47.65 - $57.25
Stock options outstanding and stock options exercisable
Stock options, range of exercise prices, low end of range (in dollars per share)	47.65
Stock options, range of exercise prices, high end of range (in dollars per share)	$ 57.25
Stock options outstanding (in shares) | shares	665
Options Outstanding, Weighted Average Remaining Contractual Term (in years)	7 years 2 months 12 days
Options Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 54.69
Options Exercisable (in shares) | shares	299
Options Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 54.06
Range of Exercise Prices $57.45 - $69.00
Stock options outstanding and stock options exercisable
Stock options, range of exercise prices, low end of range (in dollars per share)	57.45
Stock options, range of exercise prices, high end of range (in dollars per share)	$ 69.00
Stock options outstanding (in shares) | shares	255
Options Outstanding, Weighted Average Remaining Contractual Term (in years)	7 years 4 months 24 days
Options Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 63.23
Options Exercisable (in shares) | shares	56
Options Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 63.89
Range of Exercise Prices $70.06 - $70.06
Stock options outstanding and stock options exercisable
Stock options, range of exercise prices, low end of range (in dollars per share)	70.06
Stock options, range of exercise prices, high end of range (in dollars per share)	$ 70.06
Stock options outstanding (in shares) | shares	661
Options Outstanding, Weighted Average Remaining Contractual Term (in years)	8 years 2 months 12 days
Options Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 70.06
Options Exercisable (in shares) | shares	165
Options Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 70.06
Range of Exercise Prices $70.54 - $135.03
Stock options outstanding and stock options exercisable
Stock options, range of exercise prices, low end of range (in dollars per share)	70.54
Stock options, range of exercise prices, high end of range (in dollars per share)	$ 135.03
Stock options outstanding (in shares) | shares	363
Options Outstanding, Weighted Average Remaining Contractual Term (in years)	9 years
Options Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 114.18
Options Exercisable (in shares) | shares	20
Options Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 109.79
Range of Exercise Prices $135.48 - $141.13
Stock options outstanding and stock options exercisable
Stock options, range of exercise prices, low end of range (in dollars per share)	135.48
Stock options, range of exercise prices, high end of range (in dollars per share)	$ 141.13
Stock options outstanding (in shares) | shares	829
Options Outstanding, Weighted Average Remaining Contractual Term (in years)	9 years 2 months 12 days
Options Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 135.55
Options Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 0.00