Earnings Per Share - Diluted Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Numerator:
Income (loss) from continuing operations	$ 64,000,000	$ 88,000,000	$ 87,000,000	$ 125,000,000
Preferred Stock Dividends Income Statement Impact Included in Diluted Earnings Per Share From Continuing Operations	7,000,000	0	13,000,000	25,000,000
Income from continuing operations attributable to NCR common stockholders	57,000,000	88,000,000	74,000,000	100,000,000
Loss from discontinued operations, net of tax	0	0	0	0
Net income attributable to NCR common stockholders	$ 57,000,000	$ 88,000,000	$ 74,000,000	$ 100,000,000
Weighted average outstanding shares of common stock (in shares)	128,000	120,200	128,000	119,800
Dilutive effect of restricted stock units (in shares)	900	2,900	1,700	3,200
Denominator (in shares)	128,900	152,700	129,700	123,000
Diluted earnings per share:
From continuing operations (in dollars per share)	$ 0.44	$ 0.58	$ 0.57	$ 0.81
From discontinued operations (in dollars per share)	0	0	0	0
Total diluted earnings (loss) per share (in dollars per share)	$ 0.44	$ 0.58	$ 0.57	$ 0.81
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Incremental Common Shares Attributable to Dilutive Effect of Conversion of Preferred Stock	0	29,600	0	0
Incremental Common Shares Attributable to Dilutive Effect of Conversion of Preferred Stock	0	29,600	0	0
Series A Convertible Preferred Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from diluted per share count (in shares)	13,400		13,300
Restricted Stock Units (RSUs) and Stock Options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from diluted per share count (in shares)	11,400	4,700	9,900	5,100
Series A Preferred Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from diluted per share count (in shares)				29,400