Note 4. Debt

Short-Term Debt

We have a debt financing program of up to $3.0 billion through the issuance of commercial paper. Net proceeds from this program are used for general corporate purposes. At December 31, 2011 and December 31, 2012, we had $750 million and $2.5 billion of outstanding commercial paper recorded as short-term debt with weighted-average interest rates of 0.1% and 0.2%. In conjunction with this program, we have a $3.0 billion revolving credit facility expiring in July 2016. The interest rate for the credit facility is determined based on a formula using certain market rates. At December 31, 2011 and December 31, 2012, we were in compliance with the financial covenant in the credit facility, and no amounts were outstanding under the credit facility at December 31, 2011 and December 31, 2012.

Additionally, as of December 31, 2011, we had a $468 million secured promissory note outstanding recorded as short-term debt, with an interest rate of 1.0% that matured and was paid in December 2012.

The estimated fair value of the short-term debt approximated its carrying value at December 31, 2011 and December 31, 2012.

Long-Term Debt

In May 2011, we issued $3.0 billion of unsecured senior notes in three tranches as described in the table below (collectively, the Notes) (in millions):


	Outstanding Balance as of December 31, 2011			Outstanding Balance as of December 31, 2012
1.25% Notes due on May 19, 2014	$	1,000		$	1,000
2.125% Notes due on May 19, 2016		1,000			1,000
3.625% Notes due on May 19, 2021		1,000			1,000
Unamortized discount for the Notes above		(14	)		(12	)

Total	$	2,986		$	2,988

The effective interest yields of the 2014, 2016, and 2021 Notes were 1.258%, 2.241%, and 3.734%, respectively. Interest on the Notes is payable semi-annually in arrears on May 19 and November 19 of each year. We may redeem the Notes at any time in whole or from time to time in part at specified redemption prices. We are not subject to any financial covenants under the Notes. We used the net proceeds from the issuance of the Notes for general corporate purposes. The total estimated fair value of the Notes was approximately $3.2 billion at December 31, 2011 and December 31, 2012. The fair value of the Notes was determined based on observable market prices of identical instruments in markets that are not active and was categorized accordingly as Level 2 in the fair value hierarchy.

At December 31, 2012, future principal payments for the Notes were as follows (in millions):


Years ending
2013		0
2014		1,000
2015		0
2016		1,000
Thereafter		1,000

Total	$	3,000