Condensed Consolidated Statements of Operations (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Income Statement [Abstract]
Product revenue	$ 743	$ 706	$ 1,410	$ 1,276
Service revenue	792	703	1,535	1,377
Total revenue	1,535	1,409	2,945	2,653
Cost of products	550	532	1,053	977
Cost of services	559	503	1,097	987
Selling, general and administrative expenses	232	195	461	386
Research and development expenses	55	49	110	95
Total operating expenses	1,396	1,279	2,721	2,445
Income from operations	139	130	224	208
Interest expense	(26)	(8)	(47)	(17)
Other (expense), net	(3)	(5)	(1)	(7)
Income from continuing operations before income taxes	110	117	176	184
Income tax expense	23	28	25	35
Income from continuing operations	87	89	151	149
Income (loss) from discontinued operations, net of tax	0	13	(1)	4
Net income (loss)	87	102	150	153
Net income attributable to noncontrolling interests	1	0	3	1
Net income (loss) attributable to NCR	86	102	147	152
Amounts attributable to NCR common stockholders:
Income from continuing operations	86	89	148	148
Income (loss) from discontinued operations, net of tax	0	13	(1)	4
Net income (loss)	$ 86	$ 102	$ 147	$ 152
Income per share attributable to NCR common stockholders:
Basic (in dolars per share)	$ 0.52	$ 0.56	$ 0.90	$ 0.93
Diluted (in dollars per share)	$ 0.51	$ 0.54	$ 0.88	$ 0.91
Net income per common share
Basic (in dollars per share)	$ 0.52	$ 0.64	$ 0.89	$ 0.96
Diluted (in dollars per share)	$ 0.51	$ 0.62	$ 0.87	$ 0.93
Weighted average common shares outstanding
Basic (in shares)	165.2	159.0	164.5	158.6
Diluted (in shares)	168.8	163.9	168.1	163.1