Income taxes (Details 2) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Reconciliation of the U.S. federal statutory rate to effective rate:
Taxes at U.S. statutory rate	$ 49	$ 1,203	$ 1,103
U. S. statutory tax rate (as a percent)	35.00%	35.00%	35.00%
(Decreases) increases in taxes resulting from:
Non-U.S. subsidiaries taxed at other than 35%	$ (119)	$ (236)	$ (223)
Non-U.S. subsidiaries taxed at other than 35% (as a percent)	(85.60%)	(6.90%)	(7.10%)
Nondeductible goodwill	$ 191	$ 0	$ 0
Nondeductible goodwill (as a percent)	137.40%	0.00%	0.00%
State and local taxes, net of federal	$ (1)	$ 24	$ (17)
State and local taxes, net of federal (as a percent)	(0.70%)	0.70%	(0.50%)
Interest and penalties, net of tax	$ 24	$ 12	$ 12
Interest and penalties, net of tax (as a percent)	17.20%	0.40%	0.40%
U.S. research and production incentives	$ (52)	$ (95)	$ (125)
U.S. research and production incentives (as a percent)	(37.40%)	(2.70%)	(4.00%)
ESOP dividend tax benefit	$ (27)	$ (27)	$ (25)
ESOP dividend tax benefit (as a percent)	(19.40%)	(0.80%)	(0.80%)
Other-net	$ (14)	$ (7)	$ 11
Other-net (as a percent)	(10.10%)	(0.20%)	0.40%
Total of taxes at statutory rate plus increases and decreases	$ 51	$ 874	$ 736
Total of tax rates at statutory rate plus increases and decreases in the rate (as a percent)	36.40%	25.50%	23.40%
Prior year tax and interest adjustments	$ 0	$ 42	$ (21)
Prior year tax and interest adjustments (as a percent)	0.00%	1.20%	(0.70%)
Valuation allowances	$ 141	$ 0	$ (23)
Valuation allowances (as a percent)	101.40%	0.00%	(0.70%)
Provision (benefit) for income taxes	$ 192	$ 916	$ 692
Provision (benefit) for income taxes (as a percent)	137.80%	26.70%	22.00%
Income Tax Contingency [Line Items]
Unrecognized tax benefits, increase resulting from prior period tax positions	$ 55	$ 118
Cash, Cash Equivalents, and Short-term Investments	7,168	6,460	$ 7,341	$ 6,081
Pre-tax foreign currency permanent difference	130	130	10
Deferred tax assets state, net	141
Other Tax Expense (Benefit)		(26)	12
Income tax adjustment		125
Income Tax Reconciliation Settlement Benefit Including Interest			(33)
Tax Adjustments, Settlements, and Unusual Provisions			(16)
Settlement benefit, interest and penalties			(17)
Tax Correction Prior Years			$ 55
Undistributed profits of non-U.S. subsidiaries considered indefinitely reinvested	16,000
Tax Year Prior Years
Income Tax Contingency [Line Items]
Unrecognized tax benefits, increase resulting from prior period tax positions		$ 68
Non-US
Income Tax Contingency [Line Items]
Cash, Cash Equivalents, and Short-term Investments	$ 5,000