Accumulated Other Comprehensive Income (Loss) (AOCI) - Reclassifications Out of AOCI (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Total before tax	$ 38	$ 56
Income tax expense	9	7
Net income attributable to NCR common stockholders	24	8
Product
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Cost of revenue	(453)	(420)
Services
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Cost of revenue	(672)	(677)
Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Total before tax	(4)	(1)
Income tax expense	0	1
Net income attributable to NCR common stockholders	(4)	0
Reclassification out of Accumulated Other Comprehensive Income [Member] | Product
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Cost of revenue	(1)	1
Reclassification out of Accumulated Other Comprehensive Income [Member] | Services
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Cost of revenue	(3)	(2)
Reclassification out of Accumulated Other Comprehensive Income [Member] | Effective Cash Flow Hedge Loss (Gain)
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Total before tax	(1)	0
Reclassification out of Accumulated Other Comprehensive Income [Member] | Effective Cash Flow Hedge Loss (Gain) | Product
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Cost of revenue	0	0
Reclassification out of Accumulated Other Comprehensive Income [Member] | Effective Cash Flow Hedge Loss (Gain) | Services
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Cost of revenue	(1)	0
Reclassification out of Accumulated Other Comprehensive Income [Member] | Amortization of Prior Service Benefit
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Total before tax	(2)	(2)
Reclassification out of Accumulated Other Comprehensive Income [Member] | Amortization of Prior Service Benefit | Product
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Cost of revenue	0	0
Reclassification out of Accumulated Other Comprehensive Income [Member] | Amortization of Prior Service Benefit | Services
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Cost of revenue	(2)	(2)
Reclassification out of Accumulated Other Comprehensive Income [Member] | Changes in Fair Value of Effective Cash Flow Hedges
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Total before tax	(1)	1
Reclassification out of Accumulated Other Comprehensive Income [Member] | Changes in Fair Value of Effective Cash Flow Hedges | Product
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Cost of revenue	(1)	1
Reclassification out of Accumulated Other Comprehensive Income [Member] | Changes in Fair Value of Effective Cash Flow Hedges | Services
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Cost of revenue	$ 0	$ 0