Revenue from Contracts with Customers - Disaggregation of Revenue from Contracts with Customers (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Disaggregation of Revenue [Line Items]
Revenue	$ 494	$ 459	$ 478	$ 468	$ 588	$ 526	$ 544	$ 506	$ 1,899	$ 2,164	$ 2,156
Americas
Disaggregation of Revenue [Line Items]
Revenue									1,057
EMEA
Disaggregation of Revenue [Line Items]
Revenue									492	587	567
APAC
Disaggregation of Revenue [Line Items]
Revenue									350
Recurring | Americas
Disaggregation of Revenue [Line Items]
Revenue									873
Recurring | EMEA
Disaggregation of Revenue [Line Items]
Revenue									305
Recurring | APAC
Disaggregation of Revenue [Line Items]
Revenue									185
Perpetual software licenses and hardware | Americas
Disaggregation of Revenue [Line Items]
Revenue									38
Perpetual software licenses and hardware | EMEA
Disaggregation of Revenue [Line Items]
Revenue									43
Perpetual software licenses and hardware | APAC
Disaggregation of Revenue [Line Items]
Revenue									25
Consulting services | Americas
Disaggregation of Revenue [Line Items]
Revenue									146
Consulting services | EMEA
Disaggregation of Revenue [Line Items]
Revenue									144
Consulting services | APAC
Disaggregation of Revenue [Line Items]
Revenue									$ 140
Calculated under Revenue Guidance in Effect before Topic 606
Disaggregation of Revenue [Line Items]
Revenue										2,164	2,156
Calculated under Revenue Guidance in Effect before Topic 606 | Americas
Disaggregation of Revenue [Line Items]
Revenue										1,126	1,195
Calculated under Revenue Guidance in Effect before Topic 606 | EMEA
Disaggregation of Revenue [Line Items]
Revenue										587	567
Calculated under Revenue Guidance in Effect before Topic 606 | APAC
Disaggregation of Revenue [Line Items]
Revenue										451	394
Calculated under Revenue Guidance in Effect before Topic 606 | Recurring | Americas
Disaggregation of Revenue [Line Items]
Revenue										801	739
Calculated under Revenue Guidance in Effect before Topic 606 | Recurring | EMEA
Disaggregation of Revenue [Line Items]
Revenue										282	248
Calculated under Revenue Guidance in Effect before Topic 606 | Recurring | APAC
Disaggregation of Revenue [Line Items]
Revenue										171	158
Calculated under Revenue Guidance in Effect before Topic 606 | Perpetual software licenses and hardware | Americas
Disaggregation of Revenue [Line Items]
Revenue										127	234
Calculated under Revenue Guidance in Effect before Topic 606 | Perpetual software licenses and hardware | EMEA
Disaggregation of Revenue [Line Items]
Revenue										112	133
Calculated under Revenue Guidance in Effect before Topic 606 | Perpetual software licenses and hardware | APAC
Disaggregation of Revenue [Line Items]
Revenue										101	62
Calculated under Revenue Guidance in Effect before Topic 606 | Consulting services | Americas
Disaggregation of Revenue [Line Items]
Revenue										198	222
Calculated under Revenue Guidance in Effect before Topic 606 | Consulting services | EMEA
Disaggregation of Revenue [Line Items]
Revenue										193	186
Calculated under Revenue Guidance in Effect before Topic 606 | Consulting services | APAC
Disaggregation of Revenue [Line Items]
Revenue										$ 179	$ 174