Condensed Consolidating Supplemental Guarantor Information - Statement of Operations and Comprehensive Income (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Product revenue	$ 526	$ 554
Service revenue	991	924
Total revenue	1,517	1,478
Cost of products	420	424
Cost of services	677	642
Selling, general and administrative expenses	245	230
Research and development expenses	66	67
Total operating expenses	1,408	1,363
Income from operations	109	115
Interest expense	(41)	(39)
Other (expense), net	(5)	(5)
Income from continuing operations before income taxes	63	71
Income tax expense (benefit)	7	14
Income (loss) from continuing operations before earnings in subsidiaries	56	57
Equity in earnings of consolidated subsidiaries	0	0
Income from continuing operations	56	57
Income from discontinued operations, net of tax	(35)	0
Net income	21	57
Net income attributable to noncontrolling interests	1	0
Net income attributable to NCR	20	57
Total comprehensive income (loss)	36	75
Less comprehensive income (loss) attributable to noncontrolling interests	1	0
Comprehensive income attributable to NCR	35	75
Eliminations
Product revenue	(38)	(104)
Service revenue	0	0
Total revenue	(38)	(104)
Cost of products	(38)	(104)
Cost of services	0	0
Selling, general and administrative expenses	0	0
Research and development expenses	0	0
Total operating expenses	(38)	(104)
Income from operations	0	0
Interest expense	1	1
Other (expense), net	(1)	(1)
Income from continuing operations before income taxes	0	0
Income tax expense (benefit)	0	0
Income (loss) from continuing operations before earnings in subsidiaries	0	0
Equity in earnings of consolidated subsidiaries	(135)	(54)
Income from continuing operations	(135)	(54)
Income from discontinued operations, net of tax	0	0
Net income	(135)	(54)
Net income attributable to noncontrolling interests	0	0
Net income attributable to NCR	(135)	(54)
Total comprehensive income (loss)	(149)	(77)
Less comprehensive income (loss) attributable to noncontrolling interests	0
Comprehensive income attributable to NCR	(149)	(77)
Parent Issuer
Product revenue	277	281
Service revenue	517	493
Total revenue	794	774
Cost of products	229	207
Cost of services	342	338
Selling, general and administrative expenses	164	134
Research and development expenses	46	30
Total operating expenses	781	709
Income from operations	13	65
Interest expense	(39)	(39)
Other (expense), net	(3)	(17)
Income from continuing operations before income taxes	(29)	9
Income tax expense (benefit)	(8)	(2)
Income (loss) from continuing operations before earnings in subsidiaries	(21)	11
Equity in earnings of consolidated subsidiaries	76	46
Income from continuing operations	55	57
Income from discontinued operations, net of tax	(35)	0
Net income	20	57
Net income attributable to noncontrolling interests	0	0
Net income attributable to NCR	20	57
Total comprehensive income (loss)	35	75
Less comprehensive income (loss) attributable to noncontrolling interests	0
Comprehensive income attributable to NCR	35	75
Guarantor Subsidiary
Product revenue	5	40
Service revenue	8	7
Total revenue	13	47
Cost of products	4	13
Cost of services	3	2
Selling, general and administrative expenses	1	1
Research and development expenses	0	0
Total operating expenses	8	16
Income from operations	5	31
Interest expense	0	0
Other (expense), net	1	0
Income from continuing operations before income taxes	6	31
Income tax expense (benefit)	2	16
Income (loss) from continuing operations before earnings in subsidiaries	4	15
Equity in earnings of consolidated subsidiaries	59	8
Income from continuing operations	63	23
Income from discontinued operations, net of tax	0	0
Net income	63	23
Net income attributable to noncontrolling interests	0	0
Net income attributable to NCR	63	23
Total comprehensive income (loss)	62	34
Less comprehensive income (loss) attributable to noncontrolling interests	0
Comprehensive income attributable to NCR	62	34
Non-Guarantor Subsidiaries
Product revenue	282	337
Service revenue	466	424
Total revenue	748	761
Cost of products	225	308
Cost of services	332	302
Selling, general and administrative expenses	80	95
Research and development expenses	20	37
Total operating expenses	657	742
Income from operations	91	19
Interest expense	(3)	(1)
Other (expense), net	(2)	13
Income from continuing operations before income taxes	86	31
Income tax expense (benefit)	13	0
Income (loss) from continuing operations before earnings in subsidiaries	73	31
Equity in earnings of consolidated subsidiaries	0	0
Income from continuing operations	73	31
Income from discontinued operations, net of tax	0	0
Net income	73	31
Net income attributable to noncontrolling interests	1	0
Net income attributable to NCR	72	31
Total comprehensive income (loss)	88	43
Less comprehensive income (loss) attributable to noncontrolling interests	1
Comprehensive income attributable to NCR	$ 87	$ 43