Business Combination - Estimated Fair Value of Intangible Assets Acquired (Details) - Lightning Diversion Systems, Inc. $ in Thousands	Sep. 11, 2017 USD ($)
Business Acquisition [Line Items]
Estimated Fair Value (In thousands)	$ 22,400
Customer relationships
Business Acquisition [Line Items]
Useful Life (In years)	15 years
Estimated Fair Value (In thousands)	$ 21,100
Trade name
Business Acquisition [Line Items]
Useful Life (In years)	15 years
Estimated Fair Value (In thousands)	$ 1,300

The amount of identifiable intangible assets recognized as of the acquisition date.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 55
-Paragraph 37
-URI http://asc.fasb.org/extlink&oid=84160947&loc=d3e2207-128464

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=84161108&loc=d3e4845-128472

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant