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Revenue Recognition - Additional Information (Detail) - USD ($)	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Revenue, Practical Expedient, Financing Component [true false]	true
Net revenue recognized from performance obligations	$ 56,000,000
Remaining performance obligations	2,147,000,000
Impairment losses on contract assets	0	$ 0
Advance payments and deferred revenue	$ 240,000,000

X

- Definition

Advance payments and deferred revenue.

+ References

No definition available.

+ Details

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Balance Type:	credit
Period Type:	instant

X

- Definition

Amount of impairment loss for asset recognized from cost incurred to obtain or fulfill contract with customer.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 340
-SubTopic 40
-Section 50
-Paragraph 3
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=68051541&loc=SL49131252-203054

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X

- Definition

Amount of revenue recognized from performance obligation satisfied or partially satisfied in previous reporting periods. Includes, but is not limited to, change in transaction price.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 12A
-URI http://asc.fasb.org/extlink&oid=109196051&loc=SL108322424-203045

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- Definition

Indicates (true false) whether practical expedient was elected not to adjust consideration for effect of financing component when transfer and customer payment for product or service occurs within one year or less.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 22
-URI http://asc.fasb.org/extlink&oid=109196051&loc=SL49130569-203045

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Period Type:	duration

X

- Definition

Amount of transaction price allocated to performance obligation that has not been recognized as revenue.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 13
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=109196051&loc=SL49130556-203045

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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