Debt



(in millions)	March 31, 2013		December 31, 2012
5.9% Senior Notes, due 2017 ¹	400		400
6.55% Senior Notes, due 2037 ²	399		399
Commercial paper	—		457
Total debt	799		1,256
Less: short-term debt including current maturities	—		457
Long-term debt	$	799	$	799


¹	Interest payments are due semiannually on April 15 and October 15, and, as of March 31, 2013, the unamortized debt discount is $0.4 million.


²	Interest payments are due semiannually on May 15 and November 15, and, as of March 31, 2013, the unamortized debt discount is $1.3 million.

The fair value of our long-term debt borrowings were $0.9 billion as of March 31, 2013 and December 31, 2012 and was estimated based on Level 1 fair value measures, specifically quoted market prices.

Currently, we have the ability to borrow a total of $1.2 billion through our commercial paper program, which is supported by our $1.2 billion three-year credit agreement (our “credit facility”) that will terminate on July 30, 2013. We pay a commitment fee of 15 to 35 basis points for our credit facility, depending on our credit rating, whether or not amounts have been borrowed and currently pay a commitment fee of 25 basis points. The interest rate on borrowings under our credit facility is, at our option, calculated using rates that are primarily based on either the prevailing London Inter-Bank Offer Rate, the prime rate determined by the administrative agent or the Federal funds rate. For certain borrowings under this credit facility there is also a spread based on our credit rating added to the applicable rate.

As of March 31, 2013, there were no commercial paper borrowings outstanding. In connection with the special dividend in the amount of $2.50 per share on our common stock we utilized our commercial paper program in December of 2012 and as a result, commercial paper borrowings outstanding as of December 31, 2012 totaled $457 million with an average interest rate and term of 0.48% and 28 days.

Our credit facility contains certain covenants. The only financial covenant requires that our indebtedness to cash flow ratio, as defined in our credit facility, is not greater than 4 to 1, and this covenant has never been exceeded.