Other Liabilities (Schedule of Other Liabilities) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Other Liabilities [Line Items]
Accrued environmental remediation costs	$ 353	$ 316
Miscellaneous	1,760	1,943
Total other liabilities	14,687	15,508
Other Long-Term Employee Benefit Plans Defined Benefit [Member]
Other Liabilities [Line Items]
Accrued benefit costs (Note 18)	3,271	4,063
Pension Plans, Defined Benefit [Member]
Other Liabilities [Line Items]
Accrued benefit costs (Note 18)	$ 9,303	$ 9,186