Employee Benefit Plans (Summary of Estimated Future Benefit Payments) (Details) $ in Thousands	Dec. 31, 2020 USD ($)
Defined benefit pension plan
Defined Benefit Plan Disclosure [Line Items]
2021	$ 13,143
2022	13,902
2023	12,605
2024	12,221
2025	13,351
Next 5 years	52,093
Total	117,315
Other postretirement benefits plan
Defined Benefit Plan Disclosure [Line Items]
2021	12,514
2022	12,521
2023	12,351
2024	12,237
2025	12,131
Next 5 years	60,057
Total	$ 121,811

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

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (f)
-URI http://asc.fasb.org/extlink&oid=118255775&loc=d3e1928-114920

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Amount of benefit for defined benefit plan expected to be paid in next fiscal year following current fiscal year.

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

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

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

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

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