BENEFIT PLANS (Employer Contributions for Plan) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Postretirement Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Employer contributions	$ 5,280	$ 5,915	$ 7,739
2017 (estimated)	6,013
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Employer contributions	9,576	14,047	$ 5,488
Employer contributions	48,302	$ 79,960
2017 (estimated)	$ 18,875