Benefit Plans - Estimated Future Benefit Payments (Details) $ in Thousands	Dec. 31, 2018 USD ($)
Pension Benefits
Benefit payments expected to be paid over the next ten years
2019	$ 17,183
2020	16,907
2021	16,514
2022	16,096
2023	15,524
2024 to 2028	72,761
Other Benefits
Benefit payments expected to be paid over the next ten years
2019	1,205
2020	1,318
2021	1,411
2022	1,505
2023	1,592
2024 to 2028	$ 8,495

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Amount of benefits for defined benefit plan expected to be paid in five fiscal years after fifth fiscal year following latest fiscal year.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
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-Section 50
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-Subparagraph (f)
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Amount of benefits for defined benefit plan expected to be paid in next fiscal year following latest fiscal year.

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Amount of benefits for defined benefit plan expected to be paid in fifth fiscal year following latest fiscal year.

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Amount of benefits for defined benefit plan expected to be paid in fourth fiscal year following latest fiscal year.

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Amount of benefits for defined benefit plan expected to be paid in third fiscal year following latest fiscal year.

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Amount of benefits for defined benefit plan expected to be paid in second fiscal year following latest fiscal year.

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