Condensed Consolidated Statements of Operations - USD ($) shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Income Statement [Abstract]
Product revenue	$ 548.0	$ 604.0
Service revenue	896.0	872.0
Total revenue	1,444.0	1,476.0
Cost of products	442.0	483.0
Cost of services	622.0	603.0
Selling, general and administrative expenses	224.0	225.0
Research and development expenses	53.0	55.0
Restructuring-related charges	2.0	15.0
Total operating expenses	1,343.0	1,381.0
Income (loss) from operations	101.0	95.0
Interest expense	(46.0)	(44.0)
Other (expense), net	(10.0)	(7.0)
Income (loss) income from continuing operations beofre income taxes	45.0	44.0
Income tax expense	13.0	2.0
Income (loss) income from continuing operations	32.0	42.0
Net income (loss)	32.0	42.0
Net income attributable to noncontrolling interests	0.0	2.0
Net income (loss) attributable to NCR	32.0	40.0
Amounts attributable to NCR common stockholders:
Income (loss) from continuing operations	32.0	40.0
Preferred Stock Dividends, Income Statement Impact	11.0	0.0
income (loss) from continuing operations attributable to common stockholders	21.0	40.0
Income (Loss) from Discontinued Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest	0.0	0.0
Net income (loss)	$ 21.0	$ 40.0
Income per share attributable to NCR common stockholders:
Basic (in dollars per share)	$ 0.16	$ 0.24
Diluted (in dollars per share)	0.16	0.23
Net income per common share
Basic (in dollars per share)	0.16	0.24
Diluted (in dollars per share)	$ 0.16	$ 0.23
Weighted average common shares outstanding
Basic (in shares)	130.4	169.0
Diluted (in shares)	132.7	171.6