STOCK-BASED PLANS (Summary of Stock Option Activity) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Weighted Average Exercise Price
Stock based compensation expense			$ 4,954	$ 6,324
Employees Directors and Consultants Stock Options
Stock Options
Share based compensation costs capitalized	$ 200	$ 300	$ 400	1,100
Stock options outstanding at the beginning of the period (in shares)			1,176,640
Granted (in shares)			54,000
Exercised (in shares)			(357,247)
Forfeited (in shares)			(47,000)
Expired (in shares)			(1,000)
Stock options outstanding at the end of the period (in shares)	825,393		825,393
Weighted Average Exercise Price
Stock options outstanding at the beginning of the period (in dollars per share)			$ 78.87
Granted (in dollars per share)			119.18
Exercised (in dollars per share)			58.45
Forfeited (in dollars per share)			104.82
Expired (in dollars per share)			57.77
Stock options outstanding at the end of the period (in dollars per share)	$ 88.89		$ 88.89
Stock based compensation expense	$ 600	$ 1,200	$ 1,600	$ 3,500