EQUITY - Stock Options (Details)	9 Months Ended
	Sep. 30, 2017 $ / shares shares
Shares
Exercised (in shares) | shares	(49,200)
Weighted Average Exercise Price
Exercised (in dollars per share) | $ / shares	$ 27.55
Stock options
Shares
Outstanding at the beginning of the period (in shares) | shares	446,498
Granted (in shares) | shares	38,087
Exercised (in shares) | shares	(49,200)
Cancelled, expired or forfeited (in shares) | shares	(5,656)
Outstanding at the end of the period (in shares) | shares	429,729
Exercisable at the end of the period (in shares) | shares	236,026
Weighted Average Exercise Price
Outstanding at the beginning of the period (in dollars per share) | $ / shares	$ 36.49
Granted (in dollars per share) | $ / shares	49.27
Exercised (in dollars per share) | $ / shares	27.55
Cancelled, expired or forfeited (in dollars per share) | $ / shares	41.46
Outstanding at the end of the period (in dollars per share) | $ / shares	38.58
Exercisable at the end of the period (in dollars per share) | $ / shares	$ 37.33