Employee Benefit Plans - Estimated Future Benefit Payments (Details) $ in Thousands	Dec. 31, 2017 USD ($)
Defined Benefit Plans [Member]
Estimated future benefit payments [Abstract]
2018	$ 6,584
2019	5,618
2020	5,907
2021	6,039
2022	6,251
Thereafter	33,038
SERP [Member]
Estimated future benefit payments [Abstract]
2018	12,929
2019	6,039
2020	12,646
2021	3,076
2022	3,482
Thereafter	$ 13,716

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- Definition

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://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (f)
-URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920

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- Definition

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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