Description of Business and Significant Accounting Policies - Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Earnings Per Share Reconciliation [Abstract]
Income from continuing operations	$ 44	$ 102	$ (344)	$ 40	$ 38	$ 0	$ 90	$ 53	$ (154)	$ 181	$ 452
Income (loss) from discontinued operations, net of tax	(20)	(4)	0	0	(5)	15	0	0	(24)	10	(9)
Net income (loss) attributable to NCR	$ 24	$ 98	$ (344)	$ 40	$ 33	$ 15	$ 90	$ 53	(178)	191	443
Net (loss) income attributable to NCR common stockholders									(182)	191	443
Dividends on convertible preferred stock									$ (4)	$ 0	$ 0
Weighted average outstanding shares of common stock									167.6	167.9	165.4
Dilutive effect of employee stock options and restricted stock									0.0	3.3	3.9
Common stock and common stock equivalents (in shares)									167.6	171.2	169.3
Basic earnings (loss) per share [Abstract]
Basic (in dollars per share)	$ 0.27	$ 0.60	$ (2.03)	$ 0.24	$ 0.23	$ 0.00	$ 0.54	$ 0.32	$ (0.94)	$ 1.08	$ 2.73
From discontinued operations (in dollars per share)									(0.15)	0.06	(0.05)
Basic (in dollars per share)	0.15	0.58	(2.03)	0.24	0.20	0.09	0.54	0.32	(1.09)	1.14	2.68
Diluted earnings (loss) per share [Abstract]
Diluted (in dollars per share)	0.27	0.59	(2.03)	0.23	0.22	0.00	0.53	0.31	(0.94)	1.06	2.67
From discontinued operations (in dollars per share)									(0.15)	0.06	(0.05)
Total diluted earnings (loss) per share	$ 0.15	$ 0.57	$ (2.03)	$ 0.23	$ 0.19	$ 0.09	$ 0.53	$ 0.31	$ (1.09)	$ 1.12	$ 2.62
Antidilutive options to purchase excluded from computation of diluted earnings per share										0.0	0.0
Earnings Per Share, Potentially Dilutive Securities									2
WeightedAverageDilutedSharesOutstanding									172.2