8.Debt

At June 30, 2016 and September 30, 2015, we had the following unsecured long-term debt outstanding:


					Unamortized Discount and
	Principal				Debt Issuance Costs
	June 30,		September 30,		June 30,			September 30,
	2016		2015		2016			2015
	(in thousands)

Unsecured senior notes issued July 21, 2009:
Due July 21, 2016	$	40,000	$	40,000	$	(213	)	$	(498	)

Unsecured senior notes issued March 19, 2015:
Due March 19, 2025	500,000		500,000		(7,403		)	(7,965		)

	540,000		540,000		(7,616		)	(8,463		)
Less long-term debt due within one year	40,000		40,000		(766		)	(906		)

Long-term debt	$	500,000	$	500,000	$	(6,850	)	$	(7,557	)

We have $40 million senior unsecured fixed-rate notes outstanding at June 30, 2016 that matured in July 2016. The final annual principal repayment of $40 million along with interest was paid in July 2016.

On March 19, 2015, we issued $500 million of 4.65 percent 10-year unsecured senior notes. The net proceeds, after discount and issuance cost, have been or will be used for general corporate purposes, including capital expenditures associated with our rig construction program. Interest is payable semi-annually on March 15 and September 15. The debt discount is being amortized to interest expense using the effective interest method. The debt issuance costs are amortized straight-line over the stated life of the obligation, which approximates the effective yield method.

At June 30, 2016 we had a $300 million unsecured revolving credit facility with no borrowings, but there were three letters of credit outstanding in the amount of $40.3 million. This facility was terminated on July 13, 2016, and the letters of credit were transferred to a new $300 million unsecured revolving credit facility which will mature on July 13, 2021. The new facility has $75 million available to use as letters of credit. The majority of any borrowings under the facility would accrue interest at a spread over the London Interbank Offered Rate (LIBOR). We also pay a commitment fee based on the unused balance of the facility. Borrowing spreads as well as commitment fees are determined according to a scale based on a ratio of our total debt to total capitalization. The spread over LIBOR ranges from 1.125 percent to 1.75 percent per annum and commitment fees range from .15 percent to .30 percent per annum. Based on our debt to total capitalization on June 30, 2016, the spread over LIBOR and commitment fees would be 1.125 percent and .15 percent, respectively. There is one financial covenant in the facility which requires us to maintain a funded leverage ratio (as defined) of less than 50 percent. The credit facility contains additional terms, conditions, restrictions, and covenants that we believe are usual and customary in unsecured debt arrangements for companies of similar size and credit quality

At June 30, 2016, we had two letters of credit outstanding, totaling $12 million that were issued to support international operations. These letters of credit were issued separately from the $300 million credit facility discussed in the preceding paragraph and do not reduce the available borrowing capacity of that facility.