| **Receivables (Tables)**   | 12 Months Ended                                                                                                                                                                                                                                                                                      |
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| **Receivables [Abstract]** |                                                                                                                                                                                                                                                                                                 |
| Receivables                | Receivables are summarized below: 2016 2015     (In millions)Accounts receivable$602 $837Unbilled costs and accrued earnings on cost-plus contracts345 343 947 1,180Less allowances for collection losses(10) (12) $937 $1,168 |

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| - References
No definition available.
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| - Definition
Tabular disclosure of the various types of trade accounts and notes receivable and for each the gross carrying value, allowance, and net carrying value as of the balance sheet date. Presentation is categorized by current, noncurrent and unclassified receivables.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.3,4) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682
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