Debt

Total debt, including the current portion of long-term debt, consisted of the following:



(millions)	March 31, 2014		December 31, 2013
5.875% senior notes due 2021	$	350	$	350
6.3% senior notes due 2016	500		500
7.75% senior notes due 2018, net of discount	500		500
7.875% senior notes due 2020, net of discount	249		249
8.375% senior notes due 2018	350		350
9.75% senior notes due 2014, net of discount	59		59
10% convertible senior notes due 2018, net of discount^(a)	72		72
Ship mortgage facility (includes $4 million of current portion of long-term debt)	24		25
Credit facilities of Oman joint ventures	—		11
Industrial revenue bonds (due 2028 through 2034)	239		239
Total	$	2,343	$	2,355

(a) In April 2014, the outstanding 10% convertible senior notes were converted to approximately 6.6 million common shares. See Note 17.

U.S. Credit Facility: Our U.S. credit facility contains a single financial covenant that would require us to maintain a minimum fixed charge coverage ratio of no less than 1.1-to-1.0 if and for so long as the excess of the borrowing base over the outstanding borrowings under the credit agreement is less than the greater of (a) $40 million and (b) 15% of the lesser of (i) the aggregate revolving commitments at such time and (ii) the borrowing base at such time. As of March 31, 2014, our fixed charge coverage ratio was 1.17-to-1.0. Because we currently satisfy the required fixed charge coverage ratio, we are not required to maintain a minimum borrowing availability under the credit facility. Taking into account the most recent borrowing base calculation delivered under the credit facility, which reflects trade receivables and inventory as of March 31, 2014, and outstanding letters of credit of $73 million as of March 31, 2014, borrowings available under the credit facility were approximately $285 million. As of March 31, 2014 and during the quarter then-ended, there were no borrowings under the facility. See Note 17 for a related subsequent event.

CGC Credit Facility: During the three months ended March 31, 2014, there was an immaterial amount of borrowings outstanding under our Canadian credit agreement and no borrowings outstanding as of March 31, 2014. The U.S. dollar equivalent of borrowings available under this agreement as of March 31, 2014 was $36 million.

Oman Credit Facilities: In June 2013, our joint ventures in Oman, which were fully consolidated at that time, each entered into separate secured credit agreements, which were guaranteed by us and our joint venture partner. As of December 31, 2013, there was $11 million in outstanding term loan borrowings under the credit agreements. During the first two months of 2014, an additional $3 million of term loans were borrowed under these agreements. In connection with our investment in UBBP on February 27, 2014, we contributed our joint ventures in Oman, and the corresponding credit facilities, to UBBP. See further description of our investment in UBBP in Note 2.

The fair value of our debt was approximately $2.718 billion as of March 31, 2014 and $2.659 billion as of December 31, 2013. The fair values were based on quoted prices for identical or similar liabilities in markets that are not active or valuation models in which all significant inputs and value drivers are observable and, as a result, are classified as Level 2 inputs. See Note 9 for further discussion on fair value measurements and classifications.

As of March 31, 2014, we were in compliance with the covenants contained in our credit facilities.