Earnings Per Share - Diluted Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Earnings Per Share [Abstract]
Income (loss) from continuing operations	$ 76	$ (344)	$ 108	$ (304)
Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Parent	0	0	0	0
Net income attributable to NCR	76	(344)	108	(304)
Preferred Stock Dividends, Income Statement Impact	0	0	(24)	0
Net Income (Loss) Available to Common Stockholders, Diluted	$ 76	$ (344)	$ 84	$ (304)
Weighted average outstanding shares of common stock (in shares)	123.8	169.6	127.1	169.3
Earnings Per Share, Potentially Dilutive Securities	28.0	0.0	0.0	0.0
Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements	2.7	0.0	2.5	0.0
Diluted (in shares)	154.5	169.6	129.6	169.3
Diluted earnings from continuing operations (in dollars per share)	$ 0.49	$ (2.03)	$ 0.65	$ (1.80)
Basic earnings from discontinued operations (in dollars per share)	0.00	0.00	0.00	0.00
Diluted (in dollars per share)	$ 0.49	$ (2.03)	$ 0.65	$ (1.80)
Anti Dilutive Series Preferred Shares Not Included In Calculation of EPS			27.8
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount		0.0	0.2
WeightedAverageDilutedSharesOutstanding	172.0		171.8