STOCK PLANS (Summary of Stock Option Activity) (Details) - Stock options	12 Months Ended
	Dec. 31, 2018 $ / shares shares
Stock Options, Shares
Balance at beginning of year | shares	1,362,448
Options granted | shares	171,843
Options exercised | shares	(101,272)
Options canceled | shares	(1,981)
Balance at end of year | shares	1,431,038
Exercisable at end of year | shares	1,070,594
Stock Options, Weighted Average Exercise Price
Balance at beginning of year, weighted average exercise price (in dollars per share) | $ / shares	$ 58.45
Shares granted, weighted average exercise price (in dollars per share) | $ / shares	90.70
Shares exercised, weighted average exercise price (in dollars per share) | $ / shares	46.20
Shares canceled, weighted average exercise price (in dollars per share) | $ / shares	58.79
Balance at end of year, weighted average exercise price (in dollars per share) | $ / shares	63.19
Exercisable at end of year, weighted average exercise price (in dollars per share) | $ / shares	$ 56.70