STOCK-BASED COMPENSATION (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
STOCK-BASED COMPENSATION
Proceeds from stock option exercises	$ 18,602	$ 20,939
Stock options
STOCK-BASED COMPENSATION
Award vesting period	3 years
Expiration period	10 years
Compensation expense	$ 900	1,800
Compensation expense, net of tax	700	1,500
Fair value of shares vested	7,600	12,200
Proceeds from stock option exercises	18,600
Actual tax benefit realized for the tax deduction from option exercises	4,800
Unrecognized compensation cost expected to be recognized in future periods	$ 1,500
Weighted-average period over which compensation cost is expected to be recognized	10 months 24 days
Stock options | Selling, research & development and administrative expenses
STOCK-BASED COMPENSATION
Compensation expense	$ 700	1,600
Restricted stock units
STOCK-BASED COMPENSATION
Compensation expense	8,300	4,700
Actual tax benefit realized for the tax deduction from option exercises	1,500
Unrecognized compensation cost expected to be recognized in future periods	$ 62,700
Weighted-average period over which compensation cost is expected to be recognized	2 years 3 months 18 days
Weighted-Average Grant-Date Fair Value
Fair value of units vested	$ 9,300	2,700
Intrinsic value of units vested	$ 11,500	$ 3,200
Restricted stock units (time-based)
STOCK-BASED COMPENSATION
Award vesting period	3 years
Restricted stock unit activity
Balance at the beginning of the period (in shares)	480,729
Granted (in shares)	176,424
Vested (in shares)	(112,515)
Forfeited (in shares)	(217)
Balance at the end of the period (in shares)	544,421
Weighted-Average Grant-Date Fair Value
Nonvested at the beginning of the period (in dollars per share)	$ 95.45
Granted (in dollars per share)	81.75
Vested (in dollars per share)	82.64
Forfeited (in dollars per share)	100.14
Nonvested at the end of the period (in dollars per share)	$ 92.11
Restricted stock units (performance-based)
STOCK-BASED COMPENSATION
Award vesting period	3 years
Assumptions used to estimate fair value of stock options granted
Dividend Yield (as a percent)	1.72%	1.30%
Expected Stock Price Volatility (as a percent)	23.80%	16.50%
Risk-free Interest Rate (as a percent)	0.31%	2.19%
Assumptions used to estimate fair value of restricted stock units granted
Fair value per stock award (in dollars per share)	$ 94.98	$ 134.97
Grant date stock price (in dollars per share)	$ 83.93	$ 104.51
Expected Stock Price Volatility (as a percent)	23.80%	16.50%
Expected average volatility of peer companies (as a percent)	48.50%	31.90%
Correlation assumption (as a percent)	63.50%	37.40%
Risk-free Interest Rate (as a percent)	0.31%	2.19%
Dividend Yield (as a percent)	1.72%	1.30%
Restricted stock unit activity
Balance at the beginning of the period (in shares)	181,680
Granted (in shares)	206,408
Forfeited (in shares)	(589)
Balance at the end of the period (in shares)	387,499
Weighted-Average Grant-Date Fair Value
Nonvested at the beginning of the period (in dollars per share)	$ 117.26
Granted (in dollars per share)	90.85
Forfeited (in dollars per share)	120.61
Nonvested at the end of the period (in dollars per share)	$ 103.23
Stock Awards Plans | Stock options
Stock options activity
Outstanding at the beginning of the period (in shares)	5,044,180
Exercised (in shares)	(292,090)
Forfeited or expired (in shares)	(6,630)
Outstanding at the end of the period (in shares)	4,745,460
Exercisable at the end of the period (in shares)	4,583,864
Weighted Average Exercise Price
Outstanding at the beginning of the period (in dollars per share)	$ 68.32
Exercised (in dollars per share)	55.16
Forfeited or expired (in dollars per share)	65.60
Outstanding at the end of the period (in dollars per share)	69.20
Exercisable at the end of the period (in dollars per share)	$ 68.43
Weighted-Average Remaining Contractual Term (Years):
Outstanding at the end of the period	5 years 3 months 18 days
Exercisable at the end of the period	5 years 1 month 6 days
Aggregate Intrinsic Value:
Outstanding at the end of the period	$ 143,971
Exercisable at the end of the period	142,195
Intrinsic Value of Options Exercised	$ 18,202	$ 14,047
Director Stock Option Plans | Stock options
Stock options activity
Outstanding at the beginning of the period (in shares)	135,251
Exercised (in shares)	(21,251)
Outstanding at the end of the period (in shares)	114,000
Exercisable at the end of the period (in shares)	114,000
Weighted Average Exercise Price
Outstanding at the beginning of the period (in dollars per share)	$ 58.45
Exercised (in dollars per share)	51.20
Outstanding at the end of the period (in dollars per share)	59.80
Exercisable at the end of the period (in dollars per share)	$ 59.80
Weighted-Average Remaining Contractual Term (Years):
Outstanding at the end of the period	3 years 2 months 12 days
Exercisable at the end of the period	3 years 2 months 12 days
Aggregate Intrinsic Value:
Outstanding at the end of the period	$ 4,530
Exercisable at the end of the period	4,530
Intrinsic Value of Options Exercised	$ 1,385	$ 51
Director Stock Option Plans | Restricted stock units
STOCK-BASED COMPENSATION
Award vesting period	1 year
Director Stock Option Plans | Restricted stock units (time-based)
Restricted stock unit activity
Granted (in shares)	11,490