Schedule I Schedule I Condensed Balance Sheet (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Cash and cash equivalents	$ 8,406	$ 9,429	$ 9,123	$ 9,800
Total current assets	21,052	20,350
Total assets	80,885	67,889	63,063
Accounts payable and accrued liabilities	6,984	6,853
Commercial paper and current maturities of long-term debt	2,713	982
Total current liabilities	27,116	23,922
Long-term debt, less current maturities	14,041	10,656
Total liabilities	47,586	39,597
Commitments and contingencies (Note 4)
Preferred stock, $0.001 par value - 10 shares authorized; no shares issued or outstanding	0	0
Common stock, $0.01 par value - 3,000 shares authorized; 1,019 and 1,039 issued and outstanding	10	10
Additional paid-in capital	66	0
Retained earnings	30,664	27,821
Accumulated other comprehensive income	438	461
Total shareholders' equity	31,178	28,292	25,825	23,606
Total liabilities and shareholders' equity	80,885	67,889
Parent [Member]
Cash and cash equivalents	1,025	1,506	916	2,309
Notes receivable from subsidiaries	2,889	0
Prepaid expenses and other current assets	225	179
Total current assets	4,139	1,685
Equity in net assets of subsidiaries	43,724	38,688
Other assets	106	77
Total assets	47,969	40,450
Accounts payable and accrued liabilities	356	351
Note payable to subsidiary	175	145
Commercial paper and current maturities of long-term debt	2,541	982
Total current liabilities	3,072	1,478
Long-term debt, less current maturities	13,602	10,656
Deferred income taxes and other liabilities	117	24
Total liabilities	16,791	12,158
Preferred stock, $0.001 par value - 10 shares authorized; no shares issued or outstanding	0	0
Common stock, $0.01 par value - 3,000 shares authorized; 1,019 and 1,039 issued and outstanding	10	10
Additional paid-in capital	66	0
Retained earnings	30,664	27,821
Accumulated other comprehensive income	438	461
Total shareholders' equity	31,178	28,292
Total liabilities and shareholders' equity	$ 47,969	$ 40,450