4. Debt

The following is a summary of debt, net of discounts (dollar amounts in thousands):


	As of March 31, 2015				As of December 31, 2014
	Balance		Interest Rate		Balance		Interest Rate
Revolving credit facility	$	301,655		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		2,433				2,522

		352,433				352,522

2013 Senior Unsecured Notes (A)		214,620		5.750%		241,960		5.750%
2014 Senior Unsecured Notes		300,000		5.500%		300,000		5.500%
Term loans		138,611		Various		138,682		Various

	$	1,882,319			$	2,201,654

(A)	These notes are Euro-denominated and reflect the exchange rate at March 31, 2015 and December 31, 2014, respectively.

As of March 31, 2015, principal payments due on our debt (which exclude the effects of any discounts or premiums recorded) are as follows (in thousands):


2015	$	211
2016		125,299
2017		320
2018		314,436
2019		125,000
Thereafter		1,314,620

Total	$	1,879,886

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 $5.5 million and $6.0 million as of March 31, 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 March 31, 2015 and therefore, there was no income statement effect recorded during the three month periods ended March 31, 2015 or 2014. 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 March 31, 2015 and December 31, 2014, we have posted $2.8 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 March 31, 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, facility 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 March 31, 2015, we were in compliance with all such financial and operating covenants.