Condensed Consolidating Supplemental Guarantor Information - Statement of Operations and Comprehensive Income (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Product revenue	$ 657	$ 708	$ 1,829	$ 1,932
Service revenue	1,006	969	2,905	2,809
Total revenue	1,663	1,677	4,734	4,741
Cost of products	528	528	1,430	1,487
Cost of services	662	672	1,955	1,951
Selling, general and administrative expenses	220	225	676	678
Research and development expenses	53	56	178	159
Restructuring Charges	0	7	0	13
Total operating expenses	1,463	1,488	4,239	4,288
Income from operations	200	189	495	453
Interest expense	(42)	(41)	(122)	(130)
Other (expense), net	(8)	(8)	(22)	(33)
Income from continuing operations before income taxes	150	140	351	290
Income tax expense (benefit)	31	31	78	75
Income (loss) from continuing operations before earnings in subsidiaries	119	109	273	215
Equity in earnings of consolidated subsidiaries	0	0	0	0
Income from continuing operations	119	109	273	215
Income from discontinued operations, net of tax	0	2	(5)	2
Net income	119	107	278	213
Net income attributable to noncontrolling interests	1	2	1	0
Net income attributable to NCR	118	105	277	213
Total comprehensive income (loss)	119	110	293	184
Less comprehensive income (loss) attributable to noncontrolling interests	(1)	1	(1)	(7)
Comprehensive income attributable to NCR	120	109	294	191
Eliminations
Product revenue	(51)	(100)	(215)	(270)
Service revenue	0	0	0	0
Total revenue	(51)	(100)	(215)	(270)
Cost of products	(51)	(100)	(215)	(270)
Cost of services	0	0	0	0
Selling, general and administrative expenses	0	0	0	0
Research and development expenses	0	0	0	0
Restructuring Charges		0		0
Total operating expenses	(51)	(100)	(215)	(270)
Income from operations	0	0	0	0
Interest expense	17	17	50	52
Other (expense), net	(17)	(17)	(50)	(52)
Income from continuing operations before income taxes	0	0	0	0
Income tax expense (benefit)	0	0	0	0
Income (loss) from continuing operations before earnings in subsidiaries	0	0	0	0
Equity in earnings of consolidated subsidiaries	(172)	(232)	(398)	(498)
Income from continuing operations	(172)	(232)	(398)	(498)
Income from discontinued operations, net of tax	0	0	0	0
Net income	(172)	(232)	(398)	(498)
Net income attributable to noncontrolling interests	0	0	0	0
Net income attributable to NCR	(172)	(232)	(398)	(498)
Total comprehensive income (loss)	(188)	(234)	(448)	(418)
Less comprehensive income (loss) attributable to noncontrolling interests	0	0	0	0
Comprehensive income attributable to NCR	(188)	(234)	(448)	(418)
Parent Issuer
Product revenue	338	358	948	910
Service revenue	427	415	1,254	1,191
Total revenue	765	773	2,202	2,101
Cost of products	264	282	728	712
Cost of services	295	323	871	893
Selling, general and administrative expenses	97	117	331	367
Research and development expenses	40	26	100	83
Restructuring Charges		4		10
Total operating expenses	696	752	2,030	2,065
Income from operations	69	21	172	36
Interest expense	(40)	(40)	(118)	(126)
Other (expense), net	1	10	10	35
Income from continuing operations before income taxes	30	(9)	64	(55)
Income tax expense (benefit)	11	2	20	(19)
Income (loss) from continuing operations before earnings in subsidiaries	19	(11)	44	(36)
Equity in earnings of consolidated subsidiaries	99	118	228	251
Income from continuing operations	118	107	272	215
Income from discontinued operations, net of tax	0	2	(5)	2
Net income	118	105	277	213
Net income attributable to noncontrolling interests	0	0	0	0
Net income attributable to NCR	118	105	277	213
Total comprehensive income (loss)	121	109	294	191
Less comprehensive income (loss) attributable to noncontrolling interests	0	0	0	0
Comprehensive income attributable to NCR	121	109	294	191
Guarantor Subsidiary
Product revenue	13	15	66	70
Service revenue	6	9	20	26
Total revenue	19	24	86	96
Cost of products	8	14	30	30
Cost of services	1	3	6	9
Selling, general and administrative expenses	1	1	3	3
Research and development expenses	0	0	0	0
Restructuring Charges		0		0
Total operating expenses	10	18	39	42
Income from operations	9	6	47	54
Interest expense	0	0	0	0
Other (expense), net	1	(6)	0	(11)
Income from continuing operations before income taxes	10	0	47	43
Income tax expense (benefit)	1	7	19	32
Income (loss) from continuing operations before earnings in subsidiaries	9	(7)	28	11
Equity in earnings of consolidated subsidiaries	73	114	170	247
Income from continuing operations	82	107	198	258
Income from discontinued operations, net of tax	0	0	0	0
Net income	82	107	198	258
Net income attributable to noncontrolling interests	0	0	0	0
Net income attributable to NCR	82	107	198	258
Total comprehensive income (loss)	91	103	233	204
Less comprehensive income (loss) attributable to noncontrolling interests	0	0	0	0
Comprehensive income attributable to NCR	91	103	233	204
Non-Guarantor Subsidiaries
Product revenue	357	435	1,030	1,222
Service revenue	573	545	1,631	1,592
Total revenue	930	980	2,661	2,814
Cost of products	307	332	887	1,015
Cost of services	366	346	1,078	1,049
Selling, general and administrative expenses	122	107	342	308
Research and development expenses	13	30	78	76
Restructuring Charges		3		3
Total operating expenses	808	818	2,385	2,451
Income from operations	122	162	276	363
Interest expense	(19)	(18)	(54)	(56)
Other (expense), net	7	5	18	(5)
Income from continuing operations before income taxes	110	149	240	302
Income tax expense (benefit)	19	22	39	62
Income (loss) from continuing operations before earnings in subsidiaries	91	127	201	240
Equity in earnings of consolidated subsidiaries	0	0	0	0
Income from continuing operations	91	127	201	240
Income from discontinued operations, net of tax	0	0	0	0
Net income	91	127	201	240
Net income attributable to noncontrolling interests	1	2	1	0
Net income attributable to NCR	90	125	200	240
Total comprehensive income (loss)	95	132	214	207
Less comprehensive income (loss) attributable to noncontrolling interests	(1)	1	(1)	(7)
Comprehensive income attributable to NCR	$ 96	$ 131	$ 215	$ 214