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Employee Retirement Plans (Tables) | 3 Months Ended
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Mar. 31, 2020
Pension plan |
Employee retirement plans |
Schedule of components of net periodic pension or other postretirement benefit cost | ​
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​ | ​ | ​ | ​ | ​ | ​
​ | ​ | ​ | March 31, | ​
​ | ​ | ​ | 2019 | ​
​ | ​ | ​ | ​ | ​ | ​
Component of net periodic pension cost: | ​ | ​ | ​ | ​ | ​
Service cost | ​ | ​ | $ | - | ​
Interest cost | ​ | ​ | ​ | 410 | ​
Expected return on plan assets | ​ | ​ | ​ | (294) | ​
Amortization of net loss | ​ | ​ | ​ | 149 | ​
Net periodic pension cost | ​ | ​ | $ | 265 | ​
Other postretirement benefit cost |
Employee retirement plans |
Schedule of components of net periodic pension or other postretirement benefit cost | ​
​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
​ | ​ | Three Months Ended | ​
​ | ​ | March 31, | ​ | March 31, | ​
​ | ​ | 2020 | ​ | 2019 | ​
​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
Component of periodic other postretirement benefit cost: | ​ | ​ | ​ | ​ | ​ | ​ | ​
Service cost | ​ | $ | 37 | ​ | $ | 37 | ​
Interest cost | ​ | ​ | 47 | ​ | ​ | 63 | ​
Amortization of net gain | ​ | ​ | (77) | ​ | ​ | (78) | ​
Net periodic other postretirement benefit cost | ​ | $ | 7 | ​ | $ | 22 | ​

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- Definition Tabular disclosure of the components of net benefit costs for pension plans and/or other employee benefit plans including service cost, interest cost, expected return on plan assets, gain (loss), prior service cost or credit, transition asset or obligation, and gain (loss) recognized due to settlements or curtailments. + 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 (h) -URI http://asc.fasb.org/extlink&oid=118255775&loc=d3e1928-114920 + Details
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