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Employee Retirement Plans (Tables) | 9 Months Ended
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Sep. 30, 2020
Pension plan |
Employee retirement plans |
Schedule of components of net periodic pension or other postretirement benefit cost | ​
​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
​ | ​ | ​ | ​ | Three Months Ended | ​ | ​ | Nine Months Ended
​ | ​ | ​ | September 30, | ​ | September 30,
​ | ​ | ​ | 2019 | ​ | 2019
​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
Component of net periodic pension cost: | ​ | ​ | ​ | ​ | ​ | ​ | ​
Service cost | ​ | ​ | $ | - | ​ | $ | -
Interest cost | ​ | ​ | ​ | 410 | ​ | ​ | 1,230
Expected return on plan assets | ​ | ​ | ​ | (294) | ​ | ​ | (882)
Amortization of net loss | ​ | ​ | ​ | 149 | ​ | ​ | 447
Net periodic pension cost | ​ | ​ | $ | 265 | ​ | $ | 795
Other postretirement benefit cost |
Employee retirement plans |
Schedule of components of net periodic pension or other postretirement benefit cost | ​
​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
​ | ​ | Three Months Ended | ​ | Nine Months Ended
​ | ​ | September 30, | ​ | September 30, | ​ | September 30, | ​ | September 30,
​ | ​ | 2020 | ​ | 2019 | ​ | 2020 | ​ | 2019
​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
Component of periodic other postretirement benefit cost: | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
Service cost | ​ | $ | 37 | ​ | $ | 37 | ​ | $ | 111 | ​ | $ | 111
Interest cost | ​ | ​ | 47 | ​ | ​ | 63 | ​ | ​ | 141 | ​ | ​ | 189
Amortization of net gain | ​ | ​ | (77) | ​ | ​ | (78) | ​ | ​ | (231) | ​ | ​ | (234)
Net periodic other postretirement benefit cost | ​ | $ | 7 | ​ | $ | 22 | ​ | $ | 21 | ​ | $ | 66

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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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