RETIREMENT PLANS - Narrative (Details) $ in Millions	12 Months Ended
	Dec. 31, 2019 USD ($) hour	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)
Defined Benefit Plan Disclosure
Eligibility for matching contribution for full time employees, period of service (at least, in days)	30 days
Eligibility for matching contribution for part time employees, period of service (at least, in hours) | hour	1,000
Employer match of employee contributions of first 3% of eligible compensation, percent	50.00%
Percentage of eligible compensation, matched 50% by employer	3.00%
Percentage of discretionary contribution made by employer (at most)	50.00%
Percentage of deferral salary contributed by employee	3.00%
Cash contribution made	$ 1.5	$ 1.9	$ 2.1
Employee bonuses	100.00%
Employer's contribution to deferred compensation plan	$ 0.2	$ 0.2	$ 0.3
Minimum
Defined Benefit Plan Disclosure
Employee contributions, percent	1.00%
Employee's contribution	3.00%
Maximum
Defined Benefit Plan Disclosure
Employee contributions, percent	80.00%
Employee's contribution	80.00%