Supplemental financial information - Amounts Reclassified out of AOCI (Details) - Reclassification out of Accumulated Other Comprehensive Income - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Net actuarial gains (losses) of defined benefit plans
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Reclassified from other comprehensive income (loss), before tax	[1],[2]	$ 17	$ 19	$ 57	$ 59
Tax Effect		(5)	(6)	(18)	(19)
Recognized within Net income, net of taxes		12	13	39	40
Prior service (cost) credit of defined benefit plans
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Reclassified from other comprehensive income (loss), before tax	[1],[2]	(1)	0	(4)	2
Tax Effect		0	0	1	(1)
Recognized within Net income, net of taxes		(1)	0	(3)	1
Derivative instruments
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Reclassified from other comprehensive income (loss), before tax		0	1	0	1
Tax Effect		0	0	0	0
Recognized within Net income, net of taxes		$ 0	$ 1	$ 0	$ 1

[1] Detailed in Note 7.

[2] Pension expense is included in COR, R&D and SG&A in the Consolidated Statements of Income