Income taxes (Details Textual) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Income Taxes (Textual) [Abstract]
Increase in valuation allowance for deferred tax assets	$ 41,000,000	$ 147,000,000
Interest and penalties related to unrecognized tax benefits recognized in income tax provision	32,000,000	30,000,000	23,000,000
Accrued interest and penalties associated with unrecognized tax benefits	99,000,000	102,000,000
Total foreign income before income taxes	3,700,000,000	3,300,000,000	3,000,000,000
Income taxes paid	321,000,000	502,000,000	595,000,000
Tax Credit Carryforward [Line Items]
Net noncurrent deferred tax liabilities	3,500,000,000	900,000,000
Decrease in unrecognized tax benefits that is reasonably possible within the succeeding twelve months due to potential tax settlements	70,000,000
Undistributed earnings of our foreign operations that are intended to be invested indefinitely outside of the United States	25,500,000,000
Additional income taxes required to be accrued and paid if earnings of foreign operations that are intended to be indefinitely invested outside of the United States were repatriated	9,100,000,000
Research Tax Credit Carryforward [Member]
Tax Credit Carryforward [Line Items]
Tax benefit of the retroactive extension of the 2012 R&D tax credit	70,000,000
Puerto Rico Excise Tax [Member]
Excise Tax Rate [Abstract]
Effective excise tax rate for 2011	4.00%
Effective excise tax rate for 2012	3.75%
Effective excise tax rate for first half of 2013	2.75%
Excise tax rate effective July 1, 2013 through 2017	4.00%
State [Member]
Tax Credit Carryforward [Line Items]
Tax credit carryforwards available to reduce income taxes	313,000,000
Tax credit carryforwards for which a full valuation allowance has been provided	202,000,000
NOL carryforwards	883,000,000
Operating loss carryforwards, valuation allowance	266,000,000
Federal [Member]
Tax Credit Carryforward [Line Items]
Tax credit carryforwards available to reduce income taxes	341,000,000
Tax credit carryforwards for which a full valuation allowance has been provided	4,000,000
NOL carryforwards	425,000,000
Operating loss carryforwards, valuation allowance	80,000,000
Foreign Tax Authority [Member]
Tax Credit Carryforward [Line Items]
NOL carryforwards	1,300,000,000
Operating loss carryforwards, valuation allowance	$ 770,000,000