Note 6—Debt

Debt consisted of the following as of the dates indicated (in millions):

	March 31,		December 31,
	2015		2014
SHORT-TERM DEBT
Commercial paper notes, bearing a weighted-average interest rate of 0.46% at December 31, 2014 (1)	$	—	$	734
Senior notes:
5.25% senior notes due June 2015	150		150
3.95% senior notes due September 2015	400		400
Other	3		3
Total short-term debt	553		1,287

LONG-TERM DEBT
Senior notes, net of unamortized discount of $17 and $18, respectively	8,758		8,757
Other	5		5
Total long-term debt	8,763		8,762
Total debt (2)	$	9,316	$	10,049

(1)

At December 31, 2014, we classified all of the borrowings under our commercial paper program as short-term as these borrowings were primarily designated as working capital borrowings, must be repaid within one year and were primarily for hedged NGL and crude oil inventory and NYMEX and ICE margin deposits.

(2)

Our fixed-rate senior notes (including current maturities) had a face value of approximately $9.3 billion as of both March 31, 2015 and December 31, 2014. We estimated the aggregate fair value of these notes as of March 31, 2015 and December 31, 2014 to be approximately $10.0 billion and $9.9 billion, respectively. Our fixed-rate senior notes are traded among institutions, and these trades are routinely published by a reporting service. Our determination of fair value is based on reported trading activity near quarter end. We estimate that the carrying value of outstanding borrowings under our credit facilities and commercial paper program approximates fair value as interest rates reflect current market rates. The fair value estimates for our senior notes, credit facilities and commercial paper program are based upon observable market data and are classified in Level 2 of the fair value hierarchy.

Credit Facilities

PAA senior unsecured 364-day revolving credit facility. In January 2015, we entered into a 364-day senior unsecured credit agreement with a borrowing capacity of $1.0 billion. Borrowings will accrue interest based, at our election, on either the Eurocurrency Rate or the Base Rate, as defined in the agreement, in each case plus a margin based on our credit rating at the applicable time.

Borrowings and Repayments

Total borrowings under our credit agreements and commercial paper program for the three months ended March 31, 2015 and 2014 were approximately $7.0 billion and $19.2 billion, respectively. Total repayments under our credit agreements and commercial paper program were approximately $7.7 billion and $19.3 billion for the three months ended March 31, 2015 and 2014, respectively. The variance in total gross borrowings and repayments is impacted by various business and financial factors including, but not limited to, the timing, average term and method of general partnership borrowing activities.

Letters of Credit

In connection with our supply and logistics activities, we provide certain suppliers with irrevocable standby letters of credit to secure our obligation for the purchase of crude oil, NGL and natural gas. Additionally, we issue letters of credit to support insurance programs and construction activities. At March 31, 2015 and December 31, 2014, we had outstanding letters of credit of $83 million and $87 million, respectively.