Income Taxes - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Income Taxes [Line Items]
Income before income taxes, income from domestic operations amount	$ 5,311,000,000	$ 4,693,000,000	$ 4,948,000,000
Income before income taxes, income from foreign operations amount	8,075,000,000	7,633,000,000	5,848,000,000
Cumulative amount of foreign subsidiaries earnings upon which U.S. income taxes have not been provided	33,300,000,000
California research and development credit carryforwards	146,000,000
California research and development credit carryforwards, valuation allowance	130,000,000
Federal and state capital loss carryforwards, valuation allowance	205,000,000
Total unrecognized tax benefits that, if recognized, would affect our effective tax rate	1,749,000,000	1,350,000,000	951,000,000
Uncertain tax positions, accrued interest and penalties	139,000,000	129,000,000
Federal
Income Taxes [Line Items]
Net operating loss carryforwards	1,048,000,000
Net operating loss carryforwards expiration date	2017
Capital loss carryforwards	483,000,000
State
Income Taxes [Line Items]
Net operating loss carryforwards	333,000,000
Net operating loss carryforwards expiration date	2013
Capital loss carryforwards	612,000,000
Foreign Tax Authority
Income Taxes [Line Items]
Net operating loss carryforwards	$ 384,000,000