4. Debt

The following is a summary of our debt (dollar amounts in thousands):


	As of June 30, 2015					As of December 31, 2014
	Balance		Interest Rate			Balance		Interest Rate
Revolving credit facility (A)	$	674,034		Variable		$	593,490		Variable
2006 Senior Unsecured Notes		125,000		Various			125,000		Various
2011 Senior Unsecured Notes		450,000		6.875	%		450,000		6.875	%
2012 Senior Unsecured Notes:
Principal amount		350,000		6.375	%		350,000		6.375	%
Unamortized premium		2,345		—			2,522		—


		352,345					352,522

2013 Senior Unsecured Notes (B)		222,940		5.750	%		241,960		5.750	%
2014 Senior Unsecured Notes		300,000		5.500	%		300,000		5.500	%
Term loans		138,542		Various			138,682		Various


	$	2,262,861				$	2,201,654

(A)	As of June 30, 2015, we had €301.0 million of outstanding borrowings on the revolving credit facility, or $335.5 million based on the exchange rate in effect at June 30, 2015.

(B)	The change in balance from period to period is due to foreign currency fluctuations. These notes are Euro-denominated and reflect the exchange rate at June 30, 2015 and December 31, 2014, respectively.

As of June 30, 2015, principal payments due for our debt (which exclude the effects of any premiums recorded) are as follows (in thousands):


2015	$	142
2016		125,299
2017		320
2018		686,815
2019		125,000
Thereafter		1,322,940


Total	$	2,260,516

During the second quarter 2010, we entered into an interest rate swap to manage our exposure to variable interest rates by fixing $65 million of our 2006 Senior Unsecured Notes, which started July 31, 2011 (date on which the interest rate turned variable) through maturity date (or July 2016), at a rate of 5.507%. We also entered into an interest rate swap to fix $60 million of our 2006 Senior Unsecured Notes which started October 31, 2011 (date on which the related interest rate turned variable) through the maturity date (or October 2016) at a rate of 5.675%. The fair value of the interest rate swaps was $4.7 million and $6.0 million as of June 30, 2015 and December 31, 2014, respectively, which is reflected in accounts payable and accrued expenses on the consolidated balance sheets.

We account for our interest rate swaps as cash flow hedges. Accordingly, the effective portion of changes in the fair value of our swaps is recorded as a component of accumulated other comprehensive income/loss on the balance sheet and reclassified into earnings in the same period, or periods, during which the hedged transactions effect earnings, while any ineffective portion is recorded through earnings immediately. We did not have any hedge ineffectiveness from inception of our interest rate swaps through June 30, 2015 and therefore, there was no income statement effect recorded during the three or six month periods ended June 30, 2015 or 2014. At June 30, 2015, we do not expect any of the current losses included in accumulated other comprehensive loss to be reclassified into earnings in the next 12 months. At June 30, 2015 and December 31, 2014, we have posted $2.5 million and $3.3 million of collateral related to our interest rate swaps, respectively, which is reflected in other assets on our consolidated balance sheets.

Covenants

Our debt facilities impose certain restrictions on us, including restrictions on our ability to: incur debts; create or incur liens; provide guarantees in respect of obligations of any other entity; make redemptions and repurchases of our capital stock; prepay, redeem or repurchase debt; engage in mergers or consolidations; enter into affiliated transactions; dispose of real estate or other assets; and change our business. In addition, the credit agreements governing our revolving credit facility and term loan limit the amount of dividends we can pay as a percentage of normalized adjusted funds from operations, as defined in the agreements, on a rolling four quarter basis. At June 30, 2015, the dividend restriction was 95% of normalized adjusted FFO. The indentures governing our senior unsecured notes also limit the amount of dividends we can pay based on the sum of 95% of funds from operations, proceeds of equity issuances and certain other net cash proceeds. Finally, our senior unsecured notes require us to maintain total unencumbered assets (as defined in the related indenture) of not less than 150% of our unsecured indebtedness.

In addition to these restrictions, the revolving credit facility and term loan contain customary financial and operating covenants, including covenants relating to our total leverage ratio, fixed charge coverage ratio, mortgage secured leverage ratio, recourse mortgage secured leverage ratio, consolidated adjusted net worth, unsecured leverage ratio, and unsecured interest coverage ratio. This facility also contains customary events of default, including among others, nonpayment of principal or interest, material inaccuracy of representations and failure to comply with our covenants. If an event of default occurs and is continuing under the facility, the entire outstanding balance may become immediately due and payable. At June 30, 2015, we were in compliance with all such financial and operating covenants.