Condensed Consolidated Statements of Operations (Unaudited) - USD ($) shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Income Statement [Abstract]
Product revenue	$ 708	$ 688	$ 1,932	$ 1,995
Service revenue	969	925	2,809	2,698
Total revenue	1,677	1,613	4,741	4,693
Cost of products	528	512	1,487	1,539
Cost of services	672	644	1,951	2,161
Selling, general and administrative expenses	225	224	678	788
Research and development expenses	56	53	159	175
Restructuring-related charges	7	12	13	33
Total operating expenses	1,488	1,445	4,288	4,696
Income (loss) from operations	189	168	453	(3)
Interest expense	(41)	(42)	(130)	(131)
Other (expense), net	(8)	(7)	(33)	(14)
Income (loss) from continuing operations before income taxes	140	119	290	(148)
Income tax expense	31	16	75	50
Income (loss) from continuing operations	109	103	215	(198)
Loss from discontinued operations, net of tax	(2)	(4)	(2)	(4)
Net income (loss)	107	99	213	(202)
Net income attributable to noncontrolling interests	2	1	0	4
Net income (loss) attributable to NCR	105	98	213	(206)
Amounts attributable to NCR common stockholders:
Income (loss) from continuing operations	107	102	215	(202)
Series A convertible preferred stock dividends	(13)	0	(37)	0
Income (loss) from continuing operations attributable to NCR common stockholders	94	102	178	(202)
Loss from discontinued operations, net of tax	(2)	(4)	(2)	(4)
Net income (loss) attributable to NCR common stockholders	$ 92	$ 98	$ 176	$ (206)
Income (loss) per common share from continuing operations
Basic (in dollars per share)	$ 0.76	$ 0.60	$ 1.41	$ (1.19)
Diluted (in dollars per share)	0.69	0.59	1.37	(1.19)
Net income (loss) per common share
Basic (in dollars per share)	0.74	0.58	1.40	(1.22)
Diluted (in dollars per share)	$ 0.68	$ 0.57	$ 1.36	$ (1.22)
Weighted average common shares outstanding
Basic (in shares)	123.9	169.8	126.0	169.5
Diluted (in shares)	155.4	172.3	156.8	169.5