PENSION AND OTHER POSTRETIREMENT PLANS(Details 3)	12 Months Ended
Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Pension Benefits
Weighted average assumptions used to determine benefit obligations:
Discount rate (as a percent)	3.52%	4.05%	4.30%
Rate of compensation increase (as a percent)	3.00%	3.00%	3.00%
Weighted average assumptions used to determine net periodic benefit cost:
Discount rate (as a percent)	4.05%	4.30%	3.90%
Rate of compensation increase (as a percent)	3.00%	3.00%	3.00%
Expected long-term rate of return (as a percent)	7.25%	7.50%	7.50%
SERP Benefits
Weighted average assumptions used to determine benefit obligations:
Discount rate (as a percent)	3.50%	4.01%	4.20%
Rate of compensation increase (as a percent)	5.00%	5.00%	5.00%
Weighted average assumptions used to determine net periodic benefit cost:
Discount rate (as a percent)	4.01%	4.20%	3.80%
Rate of compensation increase (as a percent)	5.00%	5.00%	5.00%
Expected long-term rate of return (as a percent)	0.00%	0.00%	0.00%

Weighted average rate for present value of future retirement benefits cash flows, used to determine benefit obligation of defined benefit plan.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (k)(1)
-URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920

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Weighted average rate increase of compensation, used to determine benefit obligation of defined benefit plan. Plan includes, but is not limited to, pay-related defined benefit plan.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (k)(2)
-URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920

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Weighted average rate for present value of future retirement benefits cash flows, used to determine net periodic benefit cost of defined benefit plan.

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Weighted average rate of return on plan assets, reflecting average rate of earnings expected on existing plan assets and expected contributions, used to determine net periodic benefit cost of defined benefit plan.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (k)(3)
-URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920

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Weighted average rate of compensation increase used to determine net periodic benefit cost of defined benefit plan. Plan includes, but is not limited to, pay-related defined benefit plan.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (k)(2)
-URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920

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