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Employee benefit plans (Tables) | 3 Months Ended
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Mar. 31, 2020
Employee benefit plans |
Schedule of net periodic benefit cost | The net periodic benefit cost was as follows (in thousands):
​ | ​ | ​ | ​ | ​ | ​ | ​
​ | ​ | Three Months Ended
​ | ​ | March 31,
​ |  | 2020 | ​ | 2019
Service cost |  | $ | 1,457 | ​ | $ | 1,263
Interest cost |  | ​ | 46 | ​ | ​ | 84
Expected return on plan assets |  | ​ | (30) | ​ | ​ | (60)
Amortization of prior service cost |  | ​ | 54 | ​ | ​ | 45
Amortization of actuarial losses | ​ | ​ | 167 | ​ | ​ | 66
Net periodic benefit cost |  | $ | 1,694 | ​ | $ | 1,398

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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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