STOCK-BASED COMPENSATION PLANS (Summary of Stock Option Activity) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Stock Options
Outstanding at beginning of year (in shares)	721,496
Granted (in shares)	41,337
Exercised (in shares)	(106,237)
Forfeited (in shares)	(253,600)
Expired (in shares)	(30,260)
Outstanding at end of year (in shares)	372,736	721,496
Weighted-average Exercise Price
Outstanding at beginning of year (in dollars per share)	$ 104.55
Granted (in dollars per share)	74.65
Exercised (in dollars per share)	65.91
Forfeited (in dollars per share)	121.63
Expired (in dollars per share)	106.39
Outstanding at end of year (in dollars per share)	$ 100.49	$ 104.55
Stock Options, Additional Disclosures
Weighted average remaining contractual term of stock options outstanding	4 years 8 months 12 days
Aggregate intrinsic value	$ 1,908,239
Stock options vested and expected to vest (in shares)	369,384
Stock options vested and expected to vest (in dollars per share)	$ 100.55
Weighted average remaining contractual term of stock options expected to vest	4 years 8 months 12 days
Aggregate intrinsic value of stock options expected to vest	$ 1,899,155
Stock options exercisable at the end of the period (in shares)	257,899
Stock options exercisable at the end of the period (in dollars per share)	$ 99.18
Weighted average remaining contractual term of stock options exercisable	3 years 3 months 18 days
Aggregate intrinsic value of stock options exercisable	$ 1,719,245
Intrinsic value of stock options exercised	$ 2,400,000	$ 2,400,000	$ 12,100,000