Supplemental financial information (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013		Mar. 31, 2012
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Provision for income taxes	$ (12)		$ (97)
Net income	362		265
Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Net income	17		11
Reclassification out of Accumulated Other Comprehensive Income [Member] | Accumulated Defined Benefit Plans Adjustment [Member]
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Net actuarial gains (losses) of defined benefit plans	26	[1]	19	[1]
Provision for income taxes	$ (9)		$ (8)

[1] This AOCI component is included in the computation of total employee benefit cost which is allocated to COR, R&D, SG&A and Restructuring charges/other in the Consolidated statements of income. Net actuarial gains (losses) of defined benefit plans is equal to the sum of Recognized net actuarial loss and Settlement loss as detailed in Note 7.