EARNINGS PER SHARE - (Details) - $ / shares shares in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Shares
Basic (in shares)	18,056	17,886	17,997	17,826
Effect of dilutive stock options (in shares)	653	745	668	756
Diluted (in shares)	18,709	18,631	18,665	18,582
Per Share Amount
Basic (in dollars per share)	$ 0.52	$ 0.61	$ 1.42	$ 1.51
Effect of dilutive stock options (in dollars per share)	(0.02)	(0.03)	(0.05)	(0.07)
Diluted (in dollars per share)	$ 0.50	$ 0.58	$ 1.37	$ 1.44