XML 47 R28.htm IDEA: XBRL DOCUMENT v3.8.0.1
Stock-Based Compensation (Tables)
3 Months Ended
Mar. 31, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]  
Schedule of Stock-Based Compensation
Stock-based compensation for the three months ended March 31 is as follows:
(in millions)
2018
 
2017
Stock option expense
$
1

 
$
1

Restricted stock and unit awards expense
12

 
18

Total stock-based compensation expense 
$
13

 
$
19