Earnings Per Share - Diluted Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Numerator:
Income (loss) from continuing operations	$ 31,000,000	$ 105,000,000	$ 118,000,000	$ 230,000,000
Preferred Stock Dividends Income Statement Impact Included in Diluted Earnings Per Share From Continuing Operations	6,000,000	12,000,000	19,000,000	37,000,000
Deemed Dividend on Preferred Stock Redemption	0	67,000,000	0	67,000,000
Income from continuing operations attributable to NCR common stockholders	25,000,000	26,000,000	99,000,000	126,000,000
Loss from discontinued operations, net of tax	0	(15,000,000)	0	(15,000,000)
Net income attributable to NCR common stockholders	$ 25,000,000	$ 11,000,000	$ 99,000,000	$ 111,000,000
Weighted average outstanding shares of common stock (in shares)	128,500	121,400	128,200	120,300
Dilutive effect of restricted stock units (in shares)	1,200	2,000	1,600	2,400
Denominator (in shares)	129,700	123,400	129,800	122,700
Diluted earnings per share:
From continuing operations (in dollars per share)	$ 0.19	$ 0.21	$ 0.76	$ 1.03
From discontinued operations (in dollars per share)	0	(0.12)	0	(0.12)
Total diluted earnings (loss) per share (in dollars per share)	$ 0.19	$ 0.09	$ 0.76	$ 0.90
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Incremental Common Shares Attributable to Dilutive Effect of Conversion of Preferred Stock	0	0	0	0
Deemed Dividend on Preferred Stock Redemption	$ 0	$ 67,000,000	$ 0	$ 67,000,000
Incremental Common Shares Attributable to Dilutive Effect of Conversion of Preferred Stock	0	0	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)	13,600	28,000	13,400	29,000
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)	14,100	4,500	10,500	4,400