Earnings Per Share - Diluted Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Earnings Per Share [Abstract]
Income (loss) from continuing operations	$ 107	$ 102	$ 215	$ (202)
Loss from discontinued operations, net of tax	(2)	(4)	(2)	(4)
Net income (loss) attributable to NCR	$ 105	$ 98	$ 213	$ (206)
Weighted average outstanding shares of common stock (in shares)	123,900,000	169,800,000	126,000,000	169,500,000
Dilutive effect of as-if Series A Convertible Preferred Stock (in shares)	28,400,000	0	28,000,000	0
Dilutive effect of employee stock options and restricted stock units (in shares)	3,100,000	2,500,000	2,800,000	0
Diluted (in shares)	155,400,000	172,300,000	156,800,000	169,500,000
Diluted earnings from continuing operations (in dollars per share)	$ 0.69	$ 0.59	$ 1.37	$ (1.19)
Diluted earnings from discontinued operations (in dollars per share)	(0.01)	(0.02)	(0.01)	(0.03)
Diluted (in dollars per share)	$ 0.68	$ 0.57	$ 1.36	$ (1.22)
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	0	0	100,000	0
WeightedAverageDilutedSharesOutstanding				172,000,000