Weighted average amortization period of finite-lived intangible assets acquired either individually or as part of a group of assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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-Topic 350
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Amount of assets, excluding financial assets and goodwill, that lack physical substance, having a projected indefinite period of benefit, acquired at the acquisition date.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 20
-Section 50
-Paragraph 1
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Amount of intangible assets, excluding goodwill, acquired at the acquisition date.

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

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 55
-Paragraph 37
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Business Acquisitions (Intangible Assets Acquired as Part of Business Combination) (Details) - USD ($) $ in Thousands		12 Months Ended
	Apr. 15, 2015	Dec. 31, 2016	Oct. 12, 2016
Downstream [Member]
Business Acquisition [Line Items]
Total intangible assets			$ 101,600
Schroedahl [Member]
Business Acquisition [Line Items]
Total intangible assets	$ 32,829
Trade Names [Member] \| Downstream [Member]
Business Acquisition [Line Items]
Indefinite-lived intangible assets acquired			24,100
Trade Names [Member] \| Schroedahl [Member]
Business Acquisition [Line Items]
Indefinite-lived intangible assets acquired	4,391
Customer Relationships [Member] \| Downstream [Member]
Business Acquisition [Line Items]
Finite-lived intangible assets acquired			49,600
Customer Relationships [Member] \| Schroedahl [Member]
Business Acquisition [Line Items]
Finite-lived intangible assets acquired	$ 22,185
Weighted average amortization period (in years)	7 years
Order or Aftermarket Backlog [Member] \| Downstream [Member]
Business Acquisition [Line Items]
Finite-lived intangible assets acquired			2,100
Weighted average amortization period (in years)		2 years
Order or Aftermarket Backlog [Member] \| Schroedahl [Member]
Business Acquisition [Line Items]
Finite-lived intangible assets acquired	$ 3,993
Weighted average amortization period (in years)	1 year
Technology-Based Intangible Assets [Member] \| Downstream [Member]
Business Acquisition [Line Items]
Finite-lived intangible assets acquired			$ 25,800
Weighted average amortization period (in years)		10 years
Technology-Based Intangible Assets [Member] \| Schroedahl [Member]
Business Acquisition [Line Items]
Finite-lived intangible assets acquired	$ 2,260
Weighted average amortization period (in years)	10 years
Minimum [Member] \| Customer Relationships [Member] \| Downstream [Member]
Business Acquisition [Line Items]
Weighted average amortization period (in years)		14 years
Maximum [Member] \| Customer Relationships [Member] \| Downstream [Member]
Business Acquisition [Line Items]
Weighted average amortization period (in years)		15 years