Segment Information - Revenue and Operating Income By Segments (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended				9 Months Ended
	Sep. 30, 2014		Sep. 30, 2013		Sep. 30, 2014 segment		Sep. 30, 2013
Segment Reporting Information [Line Items]
Number of Reportable Segments					4
Revenue by segment	$ 1,647		$ 1,508		$ 4,823		$ 4,453
Operating income by segment	204		185		569		496
Pension expense	1		5		2		21
Other adjustments	162	[1]	35	[1]	249	[1]	106	[1]
Income from operations	41		145		318		369
Restructuring and other asset-related charges	127		0		127		0
Acquisition Related Amortization Costs Included in Other Adjustments	29		17		89		48
Acquisiton Related Costs Included In Other Adjustments	5		14		25		44
Acquisition Related Purchase Price Adjustments	1		3		6		12
Legal Costs for OFAC and FCPA Investigations	0		1		2		2
Financial Services [Member]
Segment Reporting Information [Line Items]
Revenue by segment	899	[2]	767	[2]	2,593	[2]	2,263	[2]
Operating income by segment	144	[2]	93	[2]	384	[2]	245	[2]
Retail Solutions [Member]
Segment Reporting Information [Line Items]
Revenue by segment	489		494		1,482		1,498
Operating income by segment	24		50		108		140
Hospitality [Member]
Segment Reporting Information [Line Items]
Revenue by segment	168		161		487		450
Operating income by segment	27		26		62		74
Emerging Industries [Member]
Segment Reporting Information [Line Items]
Revenue by segment	91		86		261		242
Operating income by segment	9		16		15		37
Digital Insight [Member]
Segment Reporting Information [Line Items]
Business Combination, Pro Forma Information, Revenue of Acquiree since Acquisition Date, Actual	93				256
Segment Operting Income of Acquiree Since Acquisition	$ 27				$ 77

[1] (2) The following table presents the other adjustments for NCR:In millionsThree months ended September 30 Nine months ended September 302014 2013 2014 2013Restructuring plan$127 $— $127 $—Acquisition-related amortization of intangible assets29 17 89 48Acquisition-related costs5 14 25 44Acquisition-related purchase price adjustments1 3 6 12OFAC and FCPA investigations— 1 2 2Total other adjustments$162 $35 $249 $106

[2] For the three months ended September 30, 2014 and from the acquisition date of January 10, 2014 through September 30, 2014, Digital Insight contributed $93 million and $256 million, respectively, in revenue and $27 million and $77 million, respectively, in segment operating income to the Financial Services segment.