Debt consisted of the following (in millions):



	March 31, 2017		December 31, 2016
SHORT-TERM DEBT
Commercial paper notes, bearing a weighted-average interest rate of 1.9% and 1.6%, respectively⁽¹⁾	$	958	$	563
Senior secured hedged inventory facility, bearing a weighted-average interest rate of 2.0% and 1.8%, respectively⁽¹⁾	250		750
Senior notes:
6.13% senior notes due January 2017	—		400
Other	133		2
Total short-term debt ⁽²⁾	1,341		1,715

LONG-TERM DEBT
Senior notes, net of unamortized discounts and debt issuance costs of $74 and $76, respectively	9,876		9,874
Commercial paper notes, bearing a weighted-average interest rate of 1.6% ⁽³⁾	—		247
Other	3		3
Total long-term debt	9,879		10,124
Total debt ⁽⁴⁾	$	11,220	$	11,839


⁽¹⁾	We classified these commercial paper notes and credit facility borrowings as short-term as of March 31, 2017 and December 31, 2016, as these notes and borrowings were primarily designated as working capital borrowings, were required to be repaid within one year and were primarily for hedged NGL and crude oil inventory and NYMEX and ICE margin deposits.


⁽²⁾	As of March 31, 2017 and December 31, 2016, balance includes borrowings of $95 million and $410 million, respectively, for cash margin deposits with NYMEX and ICE, which are associated with financial derivatives used for hedging purposes.


⁽³⁾	At December 31, 2016, we classified a portion of our commercial paper notes as long-term based on our ability and intent to refinance such amounts on a long-term basis.

⁽⁴⁾

Our fixed-rate senior notes (including current maturities) had a face value of approximately $9.9 billion and $10.3 billion as of March 31, 2017 and December 31, 2016, respectively. We estimated the aggregate fair value of these notes as of March 31, 2017 and December 31, 2016 to be approximately $10.1 billion and $10.4 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 the end of the reporting period. 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.