Debt

The following is a summary of our outstanding debt.

						Balance at
(Amounts in thousands)	Maturity Date	Fixed/Variable Rate	Interest Rate at June 30, 2015			June 30, 2015		December 31, 2014
Mortgages and notes payable
1633 Broadway
	Dec-2016	Fixed ⁽¹⁾		6.15	%	$	772,100	$	772,100
	Dec-2016	Variable		1.61	%		154,160		154,160
				5.39	%		926,260		926,260
900 Third Avenue
	Nov-2017	Fixed ⁽¹⁾		5.35	%		255,000		255,000
	Nov-2017	Variable		1.77	%		19,337		19,337
				5.10	%		274,337		274,337
31 West 52nd Street (64.2% interest)
	Dec-2017	Fixed ⁽¹⁾		5.74	%		337,500		337,500
	Dec-2017	Variable		1.66	%		75,990		75,990
				4.99	%		413,490		413,490
One Market Plaza (49.0% interest)	Dec-2019	Fixed ⁽¹⁾		6.14	%		855,339		853,711
Waterview	June-2017	Fixed		5.76	%		210,000		210,000
1899 Pennsylvania Avenue	Nov-2020	Fixed		4.88	%		89,811		90,489
Liberty Place	June-2018	Fixed		4.50	%		84,000		84,000
Total mortgages and notes payable				5.51	%	$	2,853,237	$	2,852,287

(1) Represents loans with variable interest rates that have been fixed by interest rate swaps. See “Interest Rate Swaps” below.

Revolving Credit Facility

As of June 30, 2015, there were no amounts outstanding under our senior unsecured revolving credit facility and $200,000,000 was reserved under a letter of credit.

Interest Rate Swaps

We manage our market risk on variable rate debt by entering into swap agreements to fix the rate on all or a portion of the debt for varying periods through maturity. These interest rate swaps are derivative instruments that are designated as fair value hedges and are recorded on our balance sheet at fair value with changes in the fair value recognized through earnings. The following table summarizes our outstanding interest rate swaps.

	Notional				Strike			Fair Value as of
Property	Amount		Effective Date	Maturity Date	Rate			June 30, 2015		December 31, 2014
(Amounts in thousands)
1633 Broadway	$	772,100	Dec-2006 to Jun-2008	Dec-2016		4.92	%	$	46,929	$	60,191
900 Third Ave		255,000	Nov-2007 to Nov-2012	Nov-2015 to Nov-2017		4.15	%		15,884		19,158
31 W 52nd Street		337,500	Dec-2007 to Dec-2012	Dec-2015 to Dec-2017		4.49	%		24,013		28,748
One Market Plaza	$	840,000	Aug-2007 to Aug-2012	Aug-2017		5.02	%		73,647		86,099
Total interest rate swap liabilities								$	160,473	$	194,196

In the three and six months ended June 30, 2015, we recognized unrealized gains of $21,747,000 and $33,725,000, respectively, from the change in fair value of these interest rate swaps.