Quarterly Information (unaudited) Narrative (Details) - USD ($) $ / shares in Units, $ 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
Effect of Fourth Quarter Events [Line Items]
Income (loss) from operations	$ 138	$ 168	$ (266)	$ 95	$ 35	$ 41	$ 169	$ 108	$ 135	$ 353	$ 666
Net (loss) income attributable to NCR	$ 24	$ 98	$ (344)	$ 40	$ 33	$ 15	$ 90	$ 53	$ (178)	$ 191	$ 443
Net (loss) income per common share
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 (in dollars per share)	$ 0.15	$ 0.57	$ (2.03)	$ 0.23	$ 0.19	$ 0.09	$ 0.53	$ 0.31	$ (1.09)	$ 1.12	$ 2.62
Defined benefit plans, actuarial gains (losses) [Member]
Effect of Fourth Quarter Events [Line Items]
Income (loss) from operations	$ 29				$ 150
Net (loss) income attributable to NCR	$ 17				$ 74
Net (loss) income per common share
Basic (in dollars per share)	$ 0.10				$ 0.44
Diluted (in dollars per share)	$ 0.10				$ 0.43