Condensed Consolidated Statements of Operations (Unaudited) - USD ($) shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Income Statement [Abstract]
Product revenue	$ 554.0	$ 548.0
Service revenue	924.0	896.0
Total revenue	1,478.0	1,444.0
Cost of products	424.0	442.0
Cost of services	641.0	622.0
Selling, general and administrative expenses	229.0	224.0
Research and development expenses	67.0	53.0
Restructuring-related charges	0.0	2.0
Total operating expenses	1,361.0	1,343.0
Income from operations	117.0	101.0
Interest expense	(39.0)	(46.0)
Other (expense), net	(7.0)	(10.0)
Income from continuing operations before income taxes	71.0	45.0
Income tax expense	14.0	13.0
Income from continuing operations	57.0	32.0
Loss from discontinued operations, net of tax	0.0	0.0
Net income	57.0	32.0
Net income attributable to noncontrolling interests	0.0	0.0
Net income attributable to NCR	57.0	32.0
Amounts attributable to NCR common stockholders:
Income from continuing operations	57.0	32.0
Series A convertible preferred stock dividends	(12.0)	(11.0)
Deemed dividend on modification of Series A convertible preferred stock	(4.0)	0.0
Deemed dividend on preferred stock redemption	(58.0)	0.0
(Loss) income from continuing operations attributable to NCR common stockholders	(17.0)	21.0
Loss from discontinued operations, net of tax	0.0	0.0
Net (loss) income attributable to NCR common stockholders	$ (17.0)	$ 21.0
(Loss) income per common share from continuing operations
Basic earnings from continuing operations (in dollars per share)	$ (0.14)	$ 0.16
Income (Loss) from Continuing Operations, Per Diluted Share	(0.14)	0.16
Net (loss) income per common share
Basic (in dollars per share)	(0.14)	0.16
Diluted (in dollars per share)	$ (0.14)	$ 0.16
Weighted average common shares outstanding
Weighted average outstanding shares of common stock (in shares)	122.8	130.4
Diluted (in shares)	122.8	132.7