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EMPLOYEE BENEFIT PLANS (Nonunion Plan Assets) (Details) - Nonunion Defined Benefit Pension Plan |  |  | 3 Months Ended | 6 Months Ended | 12 Months Ended
--- | --- | --- | --- | --- | ---
Jul. 01, 2017 | Jan. 01, 2017 | Sep. 30, 2019 | Jun. 30, 2019 | Dec. 31, 2017 | Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2017
Nonunion Defined Benefit Pension, Supplemental Benefit, and Postretirement Health Benefit Plans |  |  |  |  |  |  |  |
Period over which the possibility of experiencing a substantial loss is limited by adequate diversification under the long-term asset allocation policy |  |  |  |  |  | 1 year |  |
Expected return on plan assets (as a percent) | 2.50% | 6.50% | 0.00% | 0.00% | 2.50% | 1.40% | 1.40% | 6.50%

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- Definition 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://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (k)(3) -URI http://asc.fasb.org/extlink&oid=118255775&loc=d3e1928-114920 + Details
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