XML 49 R35.htm IDEA: XBRL DOCUMENT v3.10.0.1
Fair Value of Financial Instruments (Tables)
9 Months Ended
Sep. 30, 2018
Fair Value Disclosures [Abstract]  
Fair Value of Financial Instruments
The fair value and carrying value of our senior notes were as follows: 
(Dollars in millions)
September 30, 2018
 
December 31, 2017
Fair Value
$
6,710

 
$
7,060

Carrying Value
7,276

 
7,218