Earnings Per Share - Basic Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Numerator:
Income (loss) from continuing operations	$ 23	$ 37
Preferred Stock Dividends Income Statement Impact Included in Diluted Earnings Per Share From Continuing Operations	6	13
Dividends on convertible preferred stock	(6)	(13)
Income from continuing operations attributable to NCR common stockholders	17	24
Loss from discontinued operations, net of tax	0	0
Net income (loss) attributable to NCR common stockholders	$ 17	$ 24
Denominator:
Weighted average outstanding shares of common stock (in shares)	128.0	119.3
Basic earnings per share:
From continuing operations (in dollars per share)	$ 0.13	$ 0.20
From discontinued operations (in dollars per share)	0	0
Total basic earnings (loss) per share (in dollars per share)	$ 0.13	$ 0.20