STOCK OPTIONS AND OTHER EQUITY AWARDS - Stock Option Activity (Details) - Stock Options - $ / shares	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Number of Shares
Outstanding at beginning of year (in shares)	1,681,645	1,499,795
Granted (in shares)	256,344	321,750
Exercised (in shares)	(161,298)	(49,400)
Forfeited/expired (in shares)	(13,200)	(90,500)
Outstanding at end of year (in shares)	1,763,491	1,681,645	1,499,795
Exercisable at end of year (in shares)	994,598	910,647
Weighted-Average Exercise Price
Outstanding at beginning of year (in dollars per share)	$ 13.46	$ 13.11
Granted (in dollars per share)	19.50	15.12
Exercised (in dollars per share)	13.54	12.24
Forfeited/expired (in dollars per share)	14.97	8.41
Outstanding at end of year (in dollars per share)	14.36	13.46	$ 13.11
Exercisable at end of year (in dollars per share)	13.21	13.00
Additional disclosure
Weighted-average fair value of options granted during the year (in dollars per share)	$ 5.97	$ 4.05	$ 2.98

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The number of shares into which fully or partially vested stock options outstanding as of the balance sheet date can be currently converted under the option plan.

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The weighted-average price as of the balance sheet date at which grantees can acquire the shares reserved for issuance on vested portions of options outstanding and currently exercisable under the stock option plan.

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For presentations that combine terminations, the number of shares under options that were cancelled during the reporting period as a result of occurrence of a terminating event specified in contractual agreements pertaining to the stock option plan or that expired.

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Weighted average price of options that were either forfeited or expired.

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Gross number of share options (or share units) granted during the period.

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The weighted average grant-date fair value of options granted during the reporting period as calculated by applying the disclosed option pricing methodology.

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Number of options outstanding, including both vested and non-vested options.

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Weighted average price at which grantees can acquire the shares reserved for issuance under the stock option plan.

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Weighted average price at which option holders acquired shares when converting their stock options into shares.

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Weighted average per share amount at which grantees can acquire shares of common stock by exercise of options.

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Number of share options (or share units) exercised during the current period.

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