Supplemental financial information - Other income (expense), net (OI&E) (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Supplemental Financial Information [Abstract]
Royalty income	[1]	$ 119	$ 0	$ 0
Income from settlements related to intellectual property infringement		0	188	0
Pension and other retiree benefit costs	[2]	(61)	(56)	(48)
Other	[3]	17	23	32
Total		$ 75	$ 155	$ (16)

[1] As of January 1, 2017, royalties are recorded in OI&E. See Note 1 for additional information.

[2] Reflects the adoption of ASU 2017-07. See Note 2 for additional information.

[3] Other includes interest and lease income, investment and currency gains and losses, and tax interest income and expense.