Mortgages and Notes Payable

The following table sets forth our mortgages and notes payable:



	June 30, 2018			December 31, 2017
Secured indebtedness	$	98,089		$	98,981
Unsecured indebtedness	1,967,062			1,923,513
Less-unamortized debt issuance costs	(10,147		)	(8,161		)
Total mortgages and notes payable, net	$	2,055,004		$	2,014,333

At June 30, 2018, our secured mortgage loans were collateralized by real estate assets with an aggregate undepreciated book value of $147.4 million.

Our $600.0 million unsecured revolving credit facility is scheduled to mature in January 2022 and includes an accordion feature that allows for an additional $400.0 million of borrowing capacity subject to additional lender commitments. Assuming no defaults have occurred, we have an option to extend the maturity for two additional six-month periods. The interest rate at our current credit ratings is LIBOR plus 100 basis points and the annual facility fee is 20 basis points. There was $142.0 million and $136.0 million outstanding under our revolving credit facility at June 30, 2018 and July 17, 2018, respectively. At both June 30, 2018 and July 17, 2018, we had $0.4 million of outstanding letters of credit, which reduces the availability on our revolving credit facility. As a result, the unused capacity of our revolving credit facility at June 30, 2018 and July 17, 2018 was $457.6 million and $463.6 million, respectively.

During the second quarter of 2018, we paid off at maturity $200.0 million principal amount of 7.5% unsecured notes.

During the first quarter of 2018, the Operating Partnership issued $350.0 million aggregate principal amount of 4.125% notes due 2028, less original issuance discount of $4.1 million. These notes were priced to yield 4.271%. Underwriting fees and other expenses were incurred that aggregated $2.9 million; these costs were deferred and will be amortized over the term of the notes.

We are currently in compliance with financial covenants with respect to our consolidated debt.

We have considered our short-term liquidity needs and the adequacy of our estimated cash flows from operating activities and other available financing sources to meet these needs. We intend to meet these short-term liquidity requirements through a combination of the following:


•	available cash and cash equivalents;


•	cash flows from operating activities;


•	issuance of debt securities by the Operating Partnership (some of which debt securities may be hedged to a fixed interest rate pursuant to the forward-starting swaps referred to in Note 6);


•	issuance of secured debt;


•	bank term loans;


•	borrowings under our revolving credit facility;


•	issuance of equity securities by the Company or the Operating Partnership; and


•	the disposition of non-core assets.