Condensed Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Statement of Comprehensive Income [Abstract]
Net (loss) income	$ (146)	$ 102	$ (125)	$ 159
Currency translation adjustments
Currency translation (losses) gains	(49)	5	(30)	29
Derivatives
Unrealized gains (losses) on derivatives	9	(6)	4	(10)
Gains on derivatives recognized during the period	(1)	(1)	0	(3)
Less income tax benefit	0	1	0	3
Employee benefit plans
Amortization of prior service benefit	(3)	(3)	(5)	(5)
Amortization of actuarial loss (benefit)	1	0	1	(1)
Less income tax benefit	0	1	1	2
Other comprehensive (loss) income	(43)	(3)	(29)	15
Total comprehensive (loss) income	(189)	99	(154)	174
Less comprehensive loss attributable to noncontrolling interests:
Net loss	(1)	0	0	0
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax, Portion Attributable to Noncontrolling Interest	(3)	0	(3)	0
Amounts attributable to noncontrolling interests	(4)	0	(3)	0
Comprehensive (loss) income attributable to NCR	$ (185)	$ 99	$ (151)	$ 174