XML 52 R42.htm IDEA: XBRL DOCUMENT v3.19.3
Revenue (Narrative) (Details)
$ in Millions
3 Months Ended 9 Months Ended
Sep. 30, 2019
USD ($)
Sep. 30, 2019
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]    
Advanced billings, revenue recognized $ 114  
Expected timing of satisfaction period 12 months 12 months
Support services | Minimum    
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]    
Period of recognition   1 year
Support services | Maximum    
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]    
Period of recognition   5 years
Business services | Minimum    
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]    
Period of recognition   1 year
Business services | Maximum    
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]    
Period of recognition   5 years