EMPLOYEE BENEFITS - POSTRETIREMENT - Narrative (Details) - USD ($) $ in Thousands		3 Months Ended	9 Months Ended
Aug. 31, 2017	Sep. 30, 2017	Sep. 30, 2017	Dec. 31, 2016
Defined Benefit Pension Plans and Defined Benefit Postretirement Plans Disclosure [Abstract]
Discount rate (as a percent)	3.55%			4.00%
Decrease in postretirement benefit obligation	$ 75,700
Postretirement benefit plan re-measurement, tax	$ 29,200	$ 29,172	$ 29,172
Postretirement benefit obligation		29,000	29,000	$ 101,500
Net accumulated gains		$ 67,500	$ 67,500	$ 25,300

The total of net gain (loss), prior service cost (credit), and transition assets (obligations), as well as minimum pension liability if still remaining, included in accumulated other comprehensive income associated with a defined benefit pension or other postretirement plan(s) because they have yet to be recognized as components of net periodic benefit cost.

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-Publisher FASB
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No definition available.

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The interest rate used to adjust for the time value of money for the plan.

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- Definition

The amount of increase or decrease due to a change in the terms of an existing plan or the initiation of a new plan. A plan amendment may increase or decrease benefits, including those attributed to years of service already rendered.

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Amount of tax expense (benefit) related to (increase) decrease in the value of the projected benefit obligation related to a change in an actuarial assumption and increase (decrease) in the value of the plan assets resulting from experience different from that assumed, that has not been recognized in net periodic benefit (cost) credit.

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- Definition

This represents the entire liability recognized in the balance sheet that is associated with other postretirement defined benefit plans (excluding pension plans).

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