STOCK-BASED COMPENSATION PLAN - Restricted Stock Activity (Details) - $ / shares	6 Months Ended
Jun. 30, 2020	Jun. 30, 2019
Weighted Average Fair Value
Vesting period of shares	3 years
Restricted Stock
Weighted Average Fair Value
Weighted average fair value nonvested shares-beginning balance (in dollars per share)	$ 31.50
Weighted average fair value nonvested shares - granted during the period (in dollars per share)	26.42
Weighted average fair value nonvested shares - cancelled/forfeited during the period (in dollars per share)	31.48
Weighted average fair value nonvested shares - vested during the period (in dollars per share)	31.49
Weighted average fair value nonvested shares - ending balance (in dollars per share)	$ 28.90
Officers & Key Employees
Weighted Average Fair Value
Vesting period of shares	3 years
Officers & Key Employees \| Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Nonvested Shares Outstanding, Beginning Balance	402,146
Granted (in shares)	225,278	181,387
Cancelled/Forfeited (in shares)	(14,867)
Vested (in shares)	(136,963)
Nonvested Shares Outstanding, Ending Balance	475,594
Directors
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Granted (in shares)	30,961	26,416
Weighted Average Fair Value
Vesting period of shares	12 months
Directors \| Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Nonvested Shares Outstanding, Beginning Balance	30,961
Granted (in shares)	36,829	30,028
Cancelled/Forfeited (in shares)	0
Vested (in shares)	(30,961)
Nonvested Shares Outstanding, Ending Balance	36,829

Period over which grantee's right to exercise award under share-based payment arrangement is no longer contingent on satisfaction of service or performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Includes, but is not limited to, combination of market, performance or service condition.

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The number of equity-based payment instruments, excluding stock (or unit) options, that were forfeited during the reporting period.

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The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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The weighted average fair value at grant date for nonvested equity-based awards issued during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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Per share or unit weighted-average fair value of nonvested award under share-based payment arrangement. Excludes share and unit options.

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The weighted average fair value as of grant date pertaining to an equity-based award plan other than a stock (or unit) option plan for which the grantee gained the right during the reporting period, by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash in accordance with the terms of the arrangement.

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

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