BENEFIT PLANS - Fair Value of Plan Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 190,397	$ 167,510	$ 195,768
Plan Assets, Excluding Cash And Net Payables
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	194,348	165,619
Plan Assets, Excluding Cash And Net Payables | Level I
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	55,164	53,483
Plan Assets, Excluding Cash And Net Payables | Level II
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	139,184	112,136
Plan Assets, Excluding Cash And Net Payables | Level III
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Mutual funds- fixed income
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	52,976	49,140
Mutual funds- fixed income | Level I
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	52,976	49,140
Mutual funds- fixed income | Level II
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Mutual funds- fixed income | Level III
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Common collective trust- equities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	52,214
Common collective trust- equities | Level I
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0
Common collective trust- equities | Level II
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	52,214
Common collective trust- equities | Level III
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0
Foreign issued corporate debt
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	7,472	14,002
Foreign issued corporate debt | Level I
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Foreign issued corporate debt | Level II
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	7,472	14,002
Foreign issued corporate debt | Level III
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
U.S. corporate debt
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	30,267	43,190
U.S. corporate debt | Level I
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
U.S. corporate debt | Level II
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	30,267	43,190
U.S. corporate debt | Level III
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Government debt
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	2,836	3,988
Government debt | Level I
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Government debt | Level II
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	2,836	3,988
Government debt | Level III
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
U.S. Treasury securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	32,902	38,657
U.S. Treasury securities | Level I
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
U.S. Treasury securities | Level II
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	32,902	38,657
U.S. Treasury securities | Level III
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Asset-backed securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	9,375	8,907
Asset-backed securities | Level I
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Asset-backed securities | Level II
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	9,375	8,907
Asset-backed securities | Level III
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Other
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	840	205
Other | Level I
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Other | Level II
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	840	205
Other | Level III
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Cash equivalents
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	5,466	7,530
Cash equivalents | Level I
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	2,188	4,343
Cash equivalents | Level II
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	3,278	3,187
Cash equivalents | Level III
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 0	$ 0