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EMPLOYEE RETIREMENT PLANS - Assumptions - General Disclosures (Details) - Defined-benefit pension plans | 12 Months Ended | 120 Months Ended
--- | --- | ---
Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2015 | Dec. 31, 2008 | Dec. 31, 2016
Assumptions |  |  |  |  |
Discount rate for obligations (as a percent) | 3.30% | 3.50% | 4.00% |  | 3.50%
Expected return on plan assets (as a percent) | 7.25% | 7.25% | 7.25% |  |
Actual annual rate of return on pension plan assets (as a percent) | 13.90% | 8.30% | (1.80%) | (32.10%) | 4.30%
Equity securities |  |  |  |  |
Assumptions |  |  |  |  |
Asset allocation (as a percent) | 50.00% |  |  |  |
Debt securities |  |  |  |  |
Assumptions |  |  |  |  |
Asset allocation (as a percent) | 30.00% |  |  |  |
Alternative investments |  |  |  |  |
Assumptions |  |  |  |  |
Asset allocation (as a percent) | 20.00% |  |  |  |
Minimum |  |  |  |  |
Assumptions |  |  |  |  |
Discount rate for obligations (as a percent) | 1.50% | 1.50% | 2.00% |  | 1.50%
Liabilities having a discount rate for obligations (as a percent) | 3.40% | 3.80% | 4.00% |  | 3.80%
Maximum |  |  |  |  |
Assumptions |  |  |  |  |
Discount rate for obligations (as a percent) | 3.60% | 4.00% | 4.30% |  | 4.00%

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- Definition Actual rate of return on plan assets reflecting the average rate of earnings on the funds invested for the benefits included in the benefit obligation. + References No definition available. + Details
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- Definition The interest rate used to adjust for the time value of money for the plan applied to the most significant portion of the liabilities. + References No definition available. + Details
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- Definition The interest rate used to adjust for the time value of money for the 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)(1) -URI http://asc.fasb.org/extlink&oid=65897934&loc=d3e1928-114920 + Details
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- Definition An assumption as to the rate of return on plan assets reflecting the average rate of earnings expected on the funds invested or to be invested to provide for the benefits included in the benefit obligation. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Expected Long-Term Rate of Return on Plan Assets -URI http://asc.fasb.org/extlink&oid=6512046 Reference 2: 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=65897934&loc=d3e1928-114920 + Details
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- Definition Target allocation of investments of this type to total plan assets presented on a weighted average basis. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 5 -Subparagraph (c)(i) -URI http://asc.fasb.org/extlink&oid=65897934&loc=d3e2446-114920 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (d)(i) -URI http://asc.fasb.org/extlink&oid=65897934&loc=d3e1928-114920 + Details
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