Major Customers and Concentrations of Credit Risk - Sales to Major Customers (Details) - Customer Concentration Risk - Revenue from Contract with Customer Benchmark	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Boeing
Revenue, Major Customer [Line Items]
Concentration percentage	16.60%	17.00%	16.30%
Lockheed Martin
Revenue, Major Customer [Line Items]
Concentration percentage	4.00%	4.40%	5.50%
Raytheon
Revenue, Major Customer [Line Items]
Concentration percentage	11.00%	11.70%	13.50%
Spirit
Revenue, Major Customer [Line Items]
Concentration percentage	12.20%	9.50%	8.20%
Top Ten Customers
Revenue, Major Customer [Line Items]
Concentration percentage	63.50%	62.90%	62.50%

For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
-SubTopic 10
-Section 50
-Paragraph 18
-URI http://asc.fasb.org/extlink&oid=99393423&loc=d3e6351-108592

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 20
-URI http://asc.fasb.org/extlink&oid=118260190&loc=d3e13531-108611

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 21
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=118260190&loc=d3e13537-108611

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
-SubTopic 10
-Section 50
-Paragraph 20
-URI http://asc.fasb.org/extlink&oid=99393423&loc=d3e6404-108592

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Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration