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, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Numerator:
Income (loss) from continuing operations	$ 35	$ (9)	$ 2	$ 21
Dividends on Series A Convertible Preferred Stock	(4)	(4)	(8)	(8)
Income (loss) from continuing operations attributable to NCR common stockholders	31	(13)	(6)	13
Income from discontinued operations, net of tax	6	0	5	0
Net income (loss) attributable to NCR common stockholders	$ 37	$ (13)	$ (1)	$ 13
Denominator:
Weighted average outstanding shares of common stock (in shares)	136.6	131.0	136.2	130.5
Dilutive effect of restricted stock units (in shares)	4.2	0.0	0.0	5.6
Weighted average diluted shares (in shares)	140.8	131.0	136.2	136.1
Diluted earnings per share:
From continuing operations (in dollars per share)	$ 0.22	$ (0.10)	$ (0.04)	$ 0.10
From discontinued operations (in dollars per share)	0.04	0	0.03	0
Total diluted earnings (loss) per share (in dollars per share)	$ 0.26	$ (0.10)	$ (0.01)	$ 0.10