STOCK-BASED PLANS (Summary of Stock Option Activity) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Weighted Average Exercise Price
Stock based compensation expense	$ 2,684	$ 1,906
Employees Directors and Consultants Stock Options
Stock Options
Stock options outstanding at the beginning of the period (in shares)	783,182
Granted (in shares)	230,000
Exercised (in shares)	(93,766)
Forfeited (in shares)	(23,200)
Expired (in shares)	0
Stock options outstanding at the end of the period (in shares)	896,216
Weighted Average Exercise Price
Stock options outstanding at the beginning of the period (in dollars per share)	$ 90.22
Granted (in dollars per share)	124.96
Exercised (in dollars per share)	65.90
Forfeited (in dollars per share)	117.11
Expired (in dollars per share)	0.00
Stock options outstanding at the end of the period (in dollars per share)	$ 100.98
Stock based compensation expense	$ 700	800
Share based compensation costs capitalized	$ 300	$ 300