XML 81 R71.htm IDEA: XBRL DOCUMENT v3.19.1
Stock-Based Compensation (Narrative) (Detail) - USD ($)
$ in Millions
3 Months Ended
Mar. 31, 2019
Mar. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Stock-based compensation expense $ 5 $ 5
Stock-based compensation expense (net of tax) $ 4 $ 4
Document Period End Date Mar. 31, 2019  
Document Fiscal Year Focus 2019