Investments and Advances (Details 1) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Affiliates [Member]
Schedule of Investments [Line Items]
Total revenues	$ 131,875	$ 136,065	$ 140,107
Income before income tax expense	24,075	23,016	23,054
Net income attributable to affiliates	15,594	16,786	16,663
Current assets	39,713	37,541	35,573
Noncurrent assets	68,593	66,065	61,855
Current liabilities	29,642	27,878	24,671
Noncurrent liabilities	19,442	19,366	19,267
Total affiliates' net equity	59,222	56,362	53,490
Parent [Member]
Schedule of Investments [Line Items]
Total revenues	63,101	65,196	68,632
Income before income tax expense	11,108	9,856	10,555
Net income attributable to affiliates	7,845	6,938	7,413
Current assets	15,156	14,732	14,695
Noncurrent assets	25,059	23,523	22,422
Current liabilities	11,587	11,093	11,040
Noncurrent liabilities	4,559	4,879	4,491
Total affiliates' net equity	$ 24,069	$ 22,283	$ 21,586