EQUITY - Stock Options (Details)	6 Months Ended
	Jun. 30, 2018 $ / shares shares
Shares
Exercised (in shares) | shares	(115,367)
Weighted Average Exercise Price
Exercised (in dollars per share) | $ / shares	$ 30.92
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	(115,367)
Cancelled, expired or forfeited (in shares) | shares	(5,000)
Outstanding at the end of the period (in shares) | shares	350,262
Exercisable at the end of the period (in shares) | shares	239,441
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	30.92
Cancelled, expired or forfeited (in dollars per share) | $ / shares	43.71
Outstanding at the end of the period (in dollars per share) | $ / shares	42.49
Exercisable at the end of the period (in dollars per share) | $ / shares	$ 41.11