DEBT

Unsecured Credit Facility— We have an unsecured credit facility, led by U.S. Bank, as administrative agent, and Wells Fargo Bank, as syndication agent. This unsecured revolving credit facility provides credit of up to $250 million. The actual amount available to us is limited by our leverage ratio, which may not exceed 3.5, and our fixed charge coverage ratio, which may not be below 1.3. As of March 31, 2015, the full amount of the facility was available to us.

Under the facility, the leverage ratio is defined as the ratio of total funded indebtedness to adjusted EBITDA (earnings before interest, income taxes, depreciation, amortization, and certain other expenses) for the prior four fiscal quarters. The fixed charge coverage ratio is defined as the ratio of adjusted EBITDA for the prior four fiscal quarters to fixed charges.

The facility is unsecured and is guaranteed by our material subsidiaries. The facility has a maturity date of August 2018. As of March 31, 2015, and December 31, 2014, there were no amounts outstanding under the facility. We were in compliance with the covenants under the credit facility as of March 31, 2015.

Unsecured Senior Notes—In April 2013, we issued $150 million aggregate principal amount of unsecured senior notes ("the Notes") pursuant to a note purchase agreement entered into in August 2012. We received proceeds of $149.3 million, net of offering costs. The Notes consist of the following series:


•	$60 million of 3.23% Senior Notes, Series A, due April 16, 2020


•	$45 million of 4.13% Senior Notes, Series B, due April 14, 2023


•	$45 million of 4.28%Senior Notes, Series C, due April 16, 2025

The Notes are senior unsecured obligations and rank equally in right of payment with any other unsubordinated unsecured indebtedness of ours. The Notes are subject to the same leverage ratio and fixed charge coverage ratio as apply under the credit facility. The obligations under the Notes are unconditionally guaranteed by our material subsidiaries.

We were in compliance with the covenants under the Notes as of March 31, 2015.

Interest is paid semiannually on April 16 and October 16 of each year. Interest expense is recorded net of any capitalized interest associated with investments in capital projects. We incurred gross interest expense of $1.7 million for both the three months ended March 31, 2015, and 2014. We capitalized $23,000 and $0.3 million of interest during the three months ended March 31, 2015, and 2014, respectively.