Quarterly Information (unaudited) Statement of Operations (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
Quarterly Financial Information Disclosure [Abstract]
Revenues	$ 1,802	$ 1,677	$ 1,620	$ 1,444	$ 1,680	$ 1,613	$ 1,604	$ 1,476	$ 6,543	$ 6,373	$ 6,591
Gross Profit	479	477	446	380	476	457	146	390
Income (loss) from operations	146	189	163	101	138	168	(266)	95	599	135	353
Income from continuing operations	68	107	76	32	44	102	(344)	40	283	(154)	181
Income (loss) from discontinued operations, net of tax	(11)	(2)	0	0	(20)	(4)	0	0	(13)	(24)	10
Net income (loss) attributable to NCR	$ 45	$ 92	$ 63	$ 21	$ 24	$ 98	$ (344)	$ 40	$ 270	$ (178)	$ 191
From continuing operations (in dollars per share)	$ 0.45	$ 0.76	$ 0.51	$ 0.16	$ 0.27	$ 0.60	$ (2.03)	$ 0.24	$ 1.86	$ (0.94)	$ 1.08
From continuing operations (in dollars per share)	0.43	0.69	0.49	0.16	0.27	0.59	(2.03)	0.23	1.80	(0.94)	1.06
Net income 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