STOCK-BASED PLANS (Summary of Stock Option Activity) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Weighted Average Exercise Price
Stock based compensation expense			$ 8,833	$ 4,954
Stock Option
Weighted Average Exercise Price
Stock based compensation expense	$ 900		2,600
Share based compensation costs capitalized	$ 300		$ 1,200
Employees Directors and Consultants Stock Options
Stock Options
Stock options outstanding at the beginning of the period (in shares)			783,182
Granted (in shares)			254,000
Exercised (in shares)			(178,052)
Forfeited (in shares)			(39,500)
Stock options outstanding at the end of the period (in shares)	819,630		819,630
Weighted Average Exercise Price
Stock options outstanding at the beginning of the period (in dollars per share)			$ 90.22
Granted (in dollars per share)			125.53
Exercised (in dollars per share)			65.81
Forfeited (in dollars per share)			121.71
Stock options outstanding at the end of the period (in dollars per share)	$ 104.95		$ 104.95
Stock based compensation expense		$ 600		1,600
Share based compensation costs capitalized		$ 200		$ 400