Description of Business and Significant Accounting Policies - Earnings Per Share (Diluted) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Earnings Per Share Reconciliation [Abstract]
Income from continuing operations	$ 68	$ 107	$ 76	$ 32	$ 44	$ 102	$ (344)	$ 40	$ 283	$ (154)	$ 181
Preferred Stock Dividends Income Statement Impact Included in Diluted Earnings Per Share From Continuing Operations									0
Income (loss) from continuing operations attributable to common stockholders									234	(158)	181
Income (loss) from discontinued operations, net of tax	$ (11)	$ (2)	$ 0	$ 0	$ (20)	$ (4)	$ 0	$ 0	(13)	(24)	10
Dividends on convertible preferred stock									(49)	(4)	0
Net income (loss) attributable to NCR common stockholders									$ 221	$ (182)	$ 191
Weighted average outstanding shares of common stock									125.6	167.6	167.9
Incremental Common Shares Attributable to Dilutive Effect of Conversion of Preferred Stock									28.2	0.0	0.0
Dilutive effect of employee stock options and restricted stock									3.6	0.0	3.3
Diluted (continuing operations)									157.4	167.6	171.2
Diluted earnings (loss) per share [Abstract]
Diluted (in dollars per share)	$ 0.43	$ 0.69	$ 0.49	$ 0.16	$ 0.27	$ 0.59	$ (2.03)	$ 0.23	$ 1.80	$ (0.94)	$ 1.06
From discontinued operations (in dollars per share)									(0.10)	(0.15)	0.06
Diluted (in dollars per share)	$ 0.35	$ 0.68	$ 0.49	$ 0.16	$ 0.15	$ 0.57	$ (2.03)	$ 0.23	$ 1.71	$ (1.09)	$ 1.12
Antidilutive options to purchase excluded from computation of diluted earnings per share									0.4	0.0	0.0
Earnings Per Share, Potentially Dilutive Securities										2
WeightedAverageDilutedSharesOutstanding										172.2