EQUITY - Stock Options (Details)	3 Months Ended
	Mar. 31, 2018 $ / shares shares
Shares
Exercised (in shares) | shares	(66,353)
Weighted Average Exercise Price
Exercised (in dollars per share) | $ / shares	$ 30.09
Stock options
Shares
Outstanding at the beginning of the period (in shares) | shares	429,729
Granted (in shares) | shares	40,900
Exercised (in shares) | shares	(66,353)
Cancelled, expired or forfeited (in shares) | shares	(5,000)
Outstanding at the end of the period (in shares) | shares	399,276
Exercisable at the end of the period (in shares) | shares	288,455
Weighted Average Exercise Price
Outstanding at the beginning of the period (in dollars per share) | $ / shares	$ 38.58
Granted (in dollars per share) | $ / shares	51.00
Exercised (in dollars per share) | $ / shares	30.09
Cancelled, expired or forfeited (in dollars per share) | $ / shares	43.71
Outstanding at the end of the period (in dollars per share) | $ / shares	41.20
Exercisable at the end of the period (in dollars per share) | $ / shares	$ 39.57