Income Taxes (Details) (USD $) In Millions, unless otherwise specified	9 Months Ended	12 Months Ended
	Sep. 30, 2014	Dec. 31, 2013
Income Tax Disclosure
Unrecognized tax benefits	$ 5,877	$ 5,816
Portion that, if recognized, would reduce tax expense and effective tax rate	3,973	4,307
Accrued interest on unrecognized tax benefits	823	975
Accrued penalties on unrecognized tax benefits	100	164
Lower Limit
Income Tax Disclosure
Reasonably possible reduction to the balance of unrecognized tax benefits in succeeding 12 months lower limit	0	0
Portion that, if recognized, would reduce tax expense and effective tax rate	0	0
Upper Limit
Income Tax Disclosure
Reasonably possible reduction to the balance of unrecognized tax benefits in succeeding 12 months upper limit	650	900
Portion that, if recognized, would reduce tax expense and effective tax rate	$ 100	$ 350