Income Taxes - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2015
Income Tax Disclosure [Abstract]
US federal statutory rate	35.00%	35.00%	35.00%	35.00%
Deferred tax assets, valuation allowances relating to net operating losses in certain countries	$ 151		$ 151		$ 162

Amount before allocation of valuation allowances of deferred tax asset attributable to deductible foreign operating loss carryforwards.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 6
-URI http://asc.fasb.org/extlink&oid=65882285&loc=d3e32621-109319

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=65882285&loc=d3e32632-109319

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 25
-Paragraph 20
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=68052875&loc=d3e28680-109314

Name:	us-gaap_DeferredTaxAssetsOperatingLossCarryforwardsForeign
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant