EMPLOYEE BENEFIT PLANS (Details 6) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Defined Benefit Plan Disclosure [Line Items]
Total (as a percent)	100.00%
Total (as a percent)		100.00%	100.00%
Total		$ 190,640	$ 192,163	$ 192,369
Estimated employer contribution in next fiscal year		$ 3,600
Percentage of investments for long-term growth, investment strategy mix		70.00%
Percentage of investments for near-term benefit payments, investment strategy mix		30.00%
Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total		$ 56,061	68,675
Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total		115,147	102,040
Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total		$ 19,432	$ 21,448
Cash [Member] | Minimum [Member]
Defined Benefit Plan Disclosure [Line Items]
Total (as a percent)	0.00%
Cash [Member] | Maximum [Member]
Defined Benefit Plan Disclosure [Line Items]
Total (as a percent)	5.00%
Common Stock [Member]
Defined Benefit Plan Disclosure [Line Items]
Total (as a percent)		21.20%	19.40%
Total		$ 40,510	$ 37,271
Common Stock [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total		$ 40,510	$ 37,271
Common Stock [Member] | Minimum [Member]
Defined Benefit Plan Disclosure [Line Items]
Total (as a percent)	0.00%
Common Stock [Member] | Maximum [Member]
Defined Benefit Plan Disclosure [Line Items]
Total (as a percent)	40.00%
Domestic Equity Securities Other [Member]
Defined Benefit Plan Disclosure [Line Items]
Total (as a percent)		20.50%	20.30%
Total		$ 39,070	$ 38,982
Domestic Equity Securities Other [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total		12,008	12,066
Domestic Equity Securities Other [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total		$ 27,062	$ 26,916
Domestic Equity Securities Other [Member] | Minimum [Member]
Defined Benefit Plan Disclosure [Line Items]
Total (as a percent)	0.00%
Domestic Equity Securities Other [Member] | Maximum [Member]
Defined Benefit Plan Disclosure [Line Items]
Total (as a percent)	40.00%
International equity [Member]
Defined Benefit Plan Disclosure [Line Items]
Total (as a percent)		22.20%	23.20%
Total		$ 42,373	$ 44,559
International equity [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total
International equity [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total		$ 42,373	$ 44,559
International equity [Member] | Minimum [Member]
Defined Benefit Plan Disclosure [Line Items]
Total (as a percent)	0.00%
International equity [Member] | Maximum [Member]
Defined Benefit Plan Disclosure [Line Items]
Total (as a percent)	30.00%
Debt securities - core fixed income [Member]
Defined Benefit Plan Disclosure [Line Items]
Total (as a percent)		24.00%	23.80%
Total		$ 45,712	$ 45,768
Debt securities - core fixed income [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total			18,322
Debt securities - core fixed income [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total		$ 45,712	$ 27,446
Debt securities - core fixed income [Member] | Minimum [Member]
Defined Benefit Plan Disclosure [Line Items]
Total (as a percent)	15.00%
Debt securities - core fixed income [Member] | Maximum [Member]
Defined Benefit Plan Disclosure [Line Items]
Total (as a percent)	50.00%
Real Estate [Member]
Defined Benefit Plan Disclosure [Line Items]
Total (as a percent)		6.60%	8.90%
Total		$ 12,565	$ 17,067
Real Estate [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total		$ 12,565	$ 17,067
Real Estate [Member] | Minimum [Member]
Defined Benefit Plan Disclosure [Line Items]
Total (as a percent)	0.00%
Real Estate [Member] | Maximum [Member]
Defined Benefit Plan Disclosure [Line Items]
Total (as a percent)	20.00%
Real Return Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Total (as a percent)	0.00%
Total (as a percent)		0.00%	1.60%
Total			$ 3,119
Real Return Funds [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total			$ 3,119
Alternative/Opportunistic/Special [Member]
Defined Benefit Plan Disclosure [Line Items]
Total (as a percent)		3.60%	2.30%
Total		$ 6,867	$ 4,381
Alternative/Opportunistic/Special [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total		$ 6,867	$ 4,381
Alternative/Opportunistic/Special [Member] | Minimum [Member]
Defined Benefit Plan Disclosure [Line Items]
Total (as a percent)	0.00%
Alternative/Opportunistic/Special [Member] | Maximum [Member]
Defined Benefit Plan Disclosure [Line Items]
Total (as a percent)	20.00%
Cash and Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Total (as a percent)		1.90%	0.50%
Total		$ 3,543	$ 1,016
Cash and Cash Equivalents [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total		$ 3,543	$ 1,016