EMPLOYEE BENEFIT PLANS - Narrative (Details)	12 Months Ended
	Dec. 31, 2020 USD ($) pension_plan	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)
Defined Benefit Plan Disclosure [Line Items]
Number of qualified defined benefit plans | pension_plan	1
Pension contribution requirements in next fiscal year	$ 0
Cost recognized	1,100,000	$ 1,000,000.0	$ 900,000
Amount of employer and related party securities included in plan assets	8,500,000	10,600,000
Contributions for 401k plan enhancement	$ 1,000,000.0	$ 900,000	$ 800,000
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Increase (decrease) in discount rate	(0.80%)
Increase (decrease) to net losses from discount rate	$ (11,200,000)
Increase (decrease) from demographic experience	(400,000)
Recognized (loss) from return on plan assest	9,300,000
Recognized (loss) from mortality rate	$ 700,000
Discount rate	2.26%	3.06%	4.11%
Expected long-term return on plan assets	5.72%	5.72%	7.17%
Percentage of  Plan Assets	100.00%	100.00%
Pension Benefits | Maximum | Defined Benefit Plan, Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Percentage of  Plan Assets	80.00%
Postretirement
Defined Benefit Plan Disclosure [Line Items]
Increase (decrease) in discount rate	(0.74%)
Increase (decrease) to net losses from discount rate	$ (200,000)
Discount rate	2.42%	3.16%	4.18%
Expected long-term return on plan assets	0.00%	0.00%	0.00%