Income Taxes - Schedule of Foreign Tax Credit Carryforward (Detail) $ in Millions	12 Months Ended
Dec. 31, 2015 USD ($)
Tax Credit Carryforward [Line Items]
Foreign tax credits	$ 2,090
Minimum [Member]
Tax Credit Carryforward [Line Items]
Foreign tax credits, year of expiration	2025
Maximum [Member]
Tax Credit Carryforward [Line Items]
Foreign tax credits, year of expiration	2026

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

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32559-109319

Reference 2: 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=6907707&loc=d3e32621-109319

Reference 3: 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=6907707&loc=d3e32632-109319

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