Comprehensive Income - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2015	Dec. 31, 2014
Amounts Reclassified Out Of Accumulated Other Comprehensive Income Loss [Abstract]
Accumulated other comprehensive gain related to intra-entity foreign currency transactions	$ 64	$ 87

Current period adjustment resulting from gains and losses on intercompany foreign currency transactions that are of a long-term-investment nature, that is, settlement is not planned or anticipated in the foreseeable future. Resulting from the entities to the transaction being consolidated, combined, or accounted for by the equity method in the reporting entity's financial statements.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 830
-SubTopic 30
-Section 45
-Paragraph 18
-URI http://asc.fasb.org/extlink&oid=6915805&loc=d3e32157-110900

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 830
-SubTopic 20
-Section 35
-Paragraph 3
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=6939497&loc=d3e30304-110892

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 830
-SubTopic 30
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6450520&loc=d3e32583-110901

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 830
-SubTopic 30
-Section 45
-Paragraph 20
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=6915805&loc=d3e32211-110900

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