Pension Benefit Plan Accountnig Methodology Changes (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2012
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cost of products	$ 550	$ 532	$ 1,053	$ 977
Cost of services	559	503	1,097	987
Selling, general and administrative expenses	232	195	461	386
Research and development expenses	55	49	110	95
Costs and Expenses	1,396	1,279	2,721	2,445
Operating Income (Loss)	139	130	224	208
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Extraordinary Items, Noncontrolling Interest	110	117	176	184
Income tax expense	23	28	25	35
Income from continuing operations	87	89	151	149
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	87	102	150	153
Net gain arising during the year	0	0	48	0
Net Income (Loss) Attributable to Parent	86	102	147	152
Income from continuing operations	86	89	148	148
Basic (in dolars per share)	$ 0.52	$ 0.56	$ 0.90	$ 0.93
Diluted (in dollars per share)	$ 0.51	$ 0.54	$ 0.88	$ 0.91
Basic (in dollars per share)	$ 0.52	$ 0.64	$ 0.89	$ 0.96
Diluted (in dollars per share)	$ 0.51	$ 0.62	$ 0.87	$ 0.93
Actuarial loss included in benefits expense	1	4	3	8
Less income tax benefit (expense)	2	1	(10)	2
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest	56	89	122	135
Comprehensive income attributable to NCR common stockholders	57	88	122	135
Retained earnings	1,231		1,231		1,084
Accumulated other comprehensive loss	(222)		(222)		(197)
Previous Accounting Guidance [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cost of products	553		1,058
Cost of services	591		1,153
Selling, general and administrative expenses	248		489
Research and development expenses	61		120
Costs and Expenses	1,453		2,820
Operating Income (Loss)	82		125
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Extraordinary Items, Noncontrolling Interest	53		77
Income tax expense	10		0
Income from continuing operations	43		77
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	43		76
Net gain arising during the year	22		80
Net Income (Loss) Attributable to Parent	42		73
Income from continuing operations	42		74
Basic (in dolars per share)	$ 0.25		$ 0.45
Diluted (in dollars per share)	$ 0.25		$ 0.44
Basic (in dollars per share)	$ 0.25		$ 0.44
Diluted (in dollars per share)	$ 0.25		$ 0.43
Actuarial loss included in benefits expense	33		64
Less income tax benefit (expense)	(14)		(36)
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest	50		116
Comprehensive income attributable to NCR common stockholders	51		116
Retained earnings	1,987		1,987
Accumulated other comprehensive loss	(986)		(986)
Scenario, Actual [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cost of products	550		1,053
Cost of services	559		1,097
Selling, general and administrative expenses	232		461
Research and development expenses	55		110
Costs and Expenses	1,396		2,721
Operating Income (Loss)	139		224
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Extraordinary Items, Noncontrolling Interest	110		176
Income from continuing operations	87		151
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	87		150
Net gain arising during the year	0		48
Net Income (Loss) Attributable to Parent	86		147
Basic (in dolars per share)	$ 0.52		$ 0.90
Diluted (in dollars per share)	$ 0.51		$ 0.88
Basic (in dollars per share)	$ 0.52		$ 0.89
Diluted (in dollars per share)	$ 0.51		$ 0.87
Actuarial loss included in benefits expense	1		3
Less income tax benefit (expense)	2		(10)
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest	56		122
Comprehensive income attributable to NCR common stockholders	57		122
Retained earnings	1,231		1,231
Accumulated other comprehensive loss	(222)		(222)
Scenario, Previously Reported [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cost of products		533		979
Cost of services		519		1,019
Selling, general and administrative expenses		203		402
Research and development expenses		53		103
Costs and Expenses		1,308		2,503
Operating Income (Loss)		101		150
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Extraordinary Items, Noncontrolling Interest		88		126
Income tax expense		21		20
Income from continuing operations		67		106
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest		80		110
Net gain arising during the year		0		0
Net Income (Loss) Attributable to Parent		80		109
Income from continuing operations		67		105
Basic (in dolars per share)		$ 0.42		$ 0.66
Diluted (in dollars per share)		$ 0.41		$ 0.64
Basic (in dollars per share)		$ 0.50		$ 0.69
Diluted (in dollars per share)		$ 0.49		$ 0.67
Actuarial loss included in benefits expense		32		63
Less income tax benefit (expense)		(6)		(12)
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest		89		134
Comprehensive income attributable to NCR common stockholders		89		135
Retained earnings					2,134
Accumulated other comprehensive loss					(1,247)
Scenario, Adjusted [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cost of products		532		977
Cost of services		503		987
Selling, general and administrative expenses		195		386
Research and development expenses		49		95
Costs and Expenses		1,279		2,445
Operating Income (Loss)		130		208
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Extraordinary Items, Noncontrolling Interest		117		184
Income from continuing operations		89		149
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest		102		153
Net gain arising during the year		0		0
Net Income (Loss) Attributable to Parent		102		152
Basic (in dolars per share)		$ 0.56		$ 0.93
Diluted (in dollars per share)		$ 0.54		$ 0.91
Basic (in dollars per share)		$ 0.64		$ 0.96
Diluted (in dollars per share)		$ 0.62		$ 0.93
Actuarial loss included in benefits expense		4		8
Less income tax benefit (expense)		1		2
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest		89		135
Comprehensive income attributable to NCR common stockholders		88		135
Retained earnings					1,084
Accumulated other comprehensive loss					$ (197)