Debt (Tables)

3 Months Ended

Mar. 31, 2015

Debt Disclosure [Abstract]

Schedule of debt

(in millions)	March 31, 2015		December 31, 2014
5.9% Senior Notes, due 2017 1	$	400	$	400
6.55% Senior Notes, due 2037 2	399		399
Commercial paper	190		—
Revolving line of credit	175		—
Total debt	1,164		799
Less: short-term debt including current maturities	365		—
Long-term debt	$	799	$	799

¹  Interest payments are due semiannually on April 15 and October 15, and, as of March 31, 2015, the unamortized debt discount is less than $1 million.

²  Interest payments are due semiannually on May 15 and November 15, and, as of March 31, 2015, the unamortized debt discount is approximately $1 million.