Debt

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



(millions)	June 30, 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	—		72
Ship mortgage facility (includes $4 million of current portion of long-term debt)	23		25
Credit facilities of Oman joint ventures	—		11
Industrial revenue bonds (due 2028 through 2034)	239		239
Total	$	2,270	$	2,355

In March 2014, we issued a notice of redemption to redeem the remaining $75 million in aggregate principal amount of outstanding 10% convertible senior notes due 2018. As of March 31, 2014, the notes were recorded on our accompanying consolidated balance sheet at $72 million, net of debt discount of $3 million. The notes could either be (1) redeemed at a stated redemption price or (2) converted into shares of our common stock. The holders of all $75 million in notes called for redemption elected to convert their notes into shares of USG’s common stock. Accordingly, in April 2014, we issued an additional 6,578,946 shares of our common stock in connection with the conversion of the notes.

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 June 30, 2014, our fixed charge coverage ratio was 1.22-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 June 30, 2014, and outstanding letters of credit of $70 million as of June 30, 2014, borrowings available under the credit facility were approximately $227 million. As of June 30, 2014 and during the quarter then-ended, there were no borrowings under the facility.

On April 17, 2014, we entered into Amendment No. 1 (the “Amendment”) to our U.S. credit facility. The Amendment, among other things, (i) deleted the provisions providing for an early maturity date in the event we either (1) have not repaid or provided for the repayment of our outstanding 9.75% senior notes due 2014 (the “2014 Notes”) by May 2, 2014 or (2) did not have at least $500 million in liquidity from May 2, 2014 until the repayment of the 2014 Notes, and (ii) revised the definition of borrowing base to add an additional reserve against the borrowing base in the amount of the unpaid principal balance of the 2014 Notes outstanding from time to time. The amounts so reserved will be available for borrowing (subject to the other terms of the credit agreement) to repay the 2014 Notes. As of June 30, 2014, $59 million in principal of the 2014 Notes remained outstanding.

During the six months ended June 30, 2014, there was an immaterial amount of borrowings outstanding under our Canadian credit agreement and no borrowings outstanding as of June 30, 2014. The U.S. dollar equivalent of borrowings available under this agreement as of June 30, 2014 was $37 million.

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 $2.467 billion as of June 30, 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 June 30, 2014, we were in compliance with the covenants contained in our credit facilities.