Employee Benefit Plans - Schedule of Amounts Recognized in Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Retirement Benefits [Abstract]
Defined Benefit Plan, Accumulated Other Comprehensive Income Net Settlement and Curtailment gain (loss), net of tax	$ (13,656)	$ (12,320)
Accumulated Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net of Tax	$ 13,656	$ 12,320

Amount, after tax, of accumulated other comprehensive income (loss) for gain (loss) of defined benefit plan, that has not been recognized in net periodic benefit (cost) credit.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 14A
-URI http://asc.fasb.org/extlink&oid=84228862&loc=SL7669686-108580

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (j)
-URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920

Name:	us-gaap_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetGainsLossesAfterTax
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant