Revenues - Disaggregation of Revenue By Product Category And Segment (Details) $ in Millions	3 Months Ended
Mar. 31, 2018 USD ($)
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	$ 977
Tangible Products
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	839
Service And Software
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	138
AIT
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	352
AIT \| Tangible Products
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	313
AIT \| Service And Software
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	39
EVM
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	625
EVM \| Tangible Products
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	526
EVM \| Service And Software
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	$ 99

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.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 32
-Paragraph 2A
-URI http://asc.fasb.org/extlink&oid=82859839&loc=SL82860478-203043

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 4
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=82913847&loc=SL49130543-203045

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=82913847&loc=SL49130539-203045

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=82913847&loc=SL49130545-203045

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration