Subsequent Events - Additional Information (Detail) (USD $)	3 Months Ended	1 Months Ended
Mar. 31, 2013	Mar. 31, 2012	Apr. 30, 2013 Subsequent Events [Member] Repayments [Member]	Apr. 30, 2013 Subsequent Events [Member] Samara-Nafta [Member]
Subsequent Event [Line Items]
Ownership interest in subsidiary				100.00%
Cash proceeds on sale of interests	$ 1,326,000,000	$ 132,000,000		$ 2,050,000,000
Corporation's proportionate interest in oil and gas assets (in percentage)				90.00%
After-tax proceeds on sale of interests after working capital and other adjustments				1,900,000,000
Repayment of borrowings under credit facilities			$ 1,620,000,000

The cash inflow from the sale of property, plant and equipment (capital expenditures), software, and other intangible assets.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 95

-Paragraph 16

-Subparagraph c

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Investing Activities

-URI http://asc.fasb.org/extlink&oid=6516133

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 95

-Paragraph 15

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 12

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=6943989&loc=d3e3179-108585

Name:	us-gaap_ProceedsFromSaleOfProductiveAssets
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration