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Long-Term Assets - Investment in Affiliates Additional Information (Details) - USD ($) $ in Millions | 1 Months Ended | 3 Months Ended | 6 Months Ended | 12 Months Ended
--- | --- | --- | --- | ---
Jan. 31, 2018 | Jun. 30, 2018 | Jul. 01, 2017 | Jun. 30, 2018 | Jul. 01, 2017 | Dec. 31, 2017
Business Acquisition [Line Items] |  |  |  |  |  |
Annual sales |  | $ 5,580.8 | $ 5,123.2 | $ 11,314.5 | $ 10,121.7 |
Lear FAWSN |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |
Percentage of voting interests acquired | 20.00% |  |  |  |  |
Fair value of previously held equity interest |  |  |  | 23.0 |  |
Lear FAWSN | Customer relationships |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |
Acquired intangible assets, weighted average useful life | 10 years |  |  |  |  |
Other Income And Expense | Lear FAWSN |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |
Consolidation of affiliate, revaluation gain |  |  |  | $ 10.0 |  |
Lear FAWSN |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |
Fair value of previously held equity interest | $ 23.0 |  |  |  |  |
Fair value of the noncontrolling interest | $ 14.0 |  |  |  |  |
Annual sales |  |  |  |  |  | $ 100.0

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- Definition Percentage of voting equity interests acquired at the acquisition date in the business combination. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=79982066&loc=d3e1392-128463 + Details
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- Definition Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 606 -SubTopic 10 -Section 50 -Paragraph 4 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=109196051&loc=SL49130543-203045 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 606 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=109196051&loc=SL49130539-203045 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 606 -SubTopic 10 -Section 50 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=109196051&loc=SL49130545-203045 + Details
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