Shareholders' Equity (Details) - USD ($) shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Class of Stock [Line Items]
Stock Repurchased and Retired During Period, Shares	7.4
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance at December 31, 2016	$ 699.0
Net income	58.0
Other comprehensive income	18.0	$ (12.0)
Stock Repurchased and Retired During Period, Value	(350.0)
Series A convertible preferred stock dividends	(12.0)
Deemed dividend on modification of Series A convertible preferred stock	(4.0)	0.0
Redemption of Series A convertible preferred stock	87.0
Adoption of share-based compensation accounting standard update	39.0
Employee stock compensation expense	19.0	13.0
Tax witholdings related to vesting of stock based awards	(22.0)	(6.0)
Proceeds from employee stock plans	3.0	$ 3.0
Balance at March 31, 2017	535.0
NCR Stockholders' Equity
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance at December 31, 2016	695.0
Net income	57.0
Other comprehensive income	18.0
Stock Repurchased and Retired During Period, Value	(350.0)
Series A convertible preferred stock dividends	(12.0)
Deemed dividend on modification of Series A convertible preferred stock	(4.0)
Redemption of Series A convertible preferred stock	87.0
Adoption of share-based compensation accounting standard update	39.0
Employee stock compensation expense	19.0
Tax witholdings related to vesting of stock based awards	(22.0)
Proceeds from employee stock plans	3.0
Balance at March 31, 2017	530.0
Non-Redeemable Noncontrolling Interests in Subsidiaries
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance at December 31, 2016	4.0
Net income	1.0
Other comprehensive income	0.0
Stock Repurchased and Retired During Period, Value	0.0
Series A convertible preferred stock dividends	0.0
Deemed dividend on modification of Series A convertible preferred stock	0.0
Redemption of Series A convertible preferred stock	0.0
Adoption of share-based compensation accounting standard update	0.0
Employee stock compensation expense	0.0
Tax witholdings related to vesting of stock based awards	0.0
Proceeds from employee stock plans	0.0
Balance at March 31, 2017	$ 5.0