Quarterly Information (unaudited) Narrative (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Effect of Fourth Quarter Events [Line Items]
Income (loss) from operations	$ 146	$ 189	$ 163	$ 101	$ 138	$ 168	$ (266)	$ 95	$ 599	$ 135	$ 353
Net (loss) income attributable to NCR	$ 45	$ 92	$ 63	$ 21	$ 24	$ 98	$ (344)	$ 40	$ 270	$ (178)	$ 191
Net income (loss) per common share
Basic (in dollars per share)	$ 0.36	$ 0.74	$ 0.51	$ 0.16	$ 0.15	$ 0.58	$ (2.03)	$ 0.24	$ 1.76	$ (1.09)	$ 1.14
Diluted (in dollars per share)	$ 0.35	$ 0.68	$ 0.49	$ 0.16	$ 0.15	$ 0.57	$ (2.03)	$ 0.23	$ 1.71	$ (1.09)	$ 1.12
Defined benefit plans, actuarial gains (losses) [Member]
Effect of Fourth Quarter Events [Line Items]
Income (loss) from operations	$ 85				$ 29
Net (loss) income attributable to NCR	$ 78				$ 18
Net income (loss) per common share
Basic (in dollars per share)	$ 0.63				$ 0.11
Diluted (in dollars per share)	$ 0.50				$ 0.11