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Business, Product and Geographical Area Information and Concentration of Risk, Narrative (Details) - productionfacilities | 3 Months Ended | 9 Months Ended | 12 Months Ended
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Sep. 30, 2019 | Sep. 30, 2018 | Sep. 30, 2019 | Sep. 30, 2018 | Dec. 31, 2018
Segment Reporting Information |  |  |  |  |
Percentage of employees covered by collective bargaining agreements | 62.00% |  | 62.00% |  |
Percentage of employees covered by collective bargaining agreements expiring within one year | 35.00% |  | 35.00% |  |
Domestic |  |  |  |  |
Segment Reporting Information |  |  |  |  |
Number of production facilities |  |  | 12 |  |
Foreign |  |  |  |  |
Segment Reporting Information |  |  |  |  |
Number of production facilities |  |  | 1 |  |
Customer Concentration Risk | Largest Customer | Sales Revenue, Net |  |  |  |  |
Segment Reporting Information |  |  |  |  |
Concentration percentages (percent) | 24.00% | 26.00% | 25.00% | 26.00% |
Customer Concentration Risk | Largest Customer | Accounts Receivable |  |  |  |  |
Segment Reporting Information |  |  |  |  |
Concentration percentages (percent) |  |  | 33.00% |  | 31.00%
Customer Concentration Risk | Second Largest Customer | Sales Revenue, Net |  |  |  |  |
Segment Reporting Information |  |  |  |  |
Concentration percentages (percent) | 19.00% | 15.00% | 16.00% | 13.00% |
Customer Concentration Risk | Second Largest Customer | Accounts Receivable |  |  |  |  |
Segment Reporting Information |  |  |  |  |
Concentration percentages (percent) |  |  | 12.00% |  | 11.00%

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- Definition 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. + References 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 + Details
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