Consolidated Statements of Stockholders' Equity (Parenthetical) $ in Thousands	3 Months Ended
Mar. 31, 2018 USD ($)
Statement of Stockholders' Equity [Abstract]
Tax provision (benefit) on pension adjustment	$ 5

Tax effect of plan amendments that occurred that has not been recognized in net periodic benefit cost.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 12
-URI http://asc.fasb.org/extlink&oid=84228862&loc=d3e640-108580

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration