On April 1, 2015, we completed a $308,000,000 refinancing of RiverHouse Apartments, a three building, 1,670 unit rental complex located in Arlington, VA. The loan is interest only at LIBOR plus 1.28% (1.52% at December 31, 2015) and matures in 2025. We realized net proceeds of approximately $43,000,000. The property was previously encumbered by a 5.43%, $195,000,000 mortgage maturing in April 2015 and a $64,000,000 mortgage at LIBOR plus 1.53% maturing in 2018.

On June 2, 2015, we completed a $205,000,000 financing in connection with the acquisition of 150 West 34th Street (see Note 4 – Acquisitions). The loan bears interest at LIBOR plus 2.25% (2.52% at December 31, 2015) and matures in 2018 with two one-year extension options.

On July 28, 2015, we completed a $580,000,000 refinancing of 100 West 33rd Street, a 1.1 million square foot property comprised of 855,000 square feet of office space and the 256,000 square foot Manhattan Mall. The loan is interest only at LIBOR plus 1.65% (1.92% at December 31, 2015) and matures in July 2020. We realized net proceeds of approximately $242,000,000.

On September 22, 2015, we upsized the loan on our 220 Central Park South development by $350,000,000 to $950,000,000. The interest rate on the loan is LIBOR plus 2.00% (2.42% at December 31, 2015) and the final maturity date is 2020. In connection with the upsizing, the standby commitment for a $500,000,000 mezzanine loan for this development has been terminated by payment of a $15,000,000 contractual termination fee, which was capitalized as a component of “development costs and construction in progress” on our consolidated balance sheet as of December 31, 2015.

On December 11, 2015, we completed a $375,000,000 refinancing of 888 Seventh Avenue, a 882,000 square foot Manhattan office building. The five-year loan is interest only at LIBOR plus 1.60% (1.92% at December 31, 2015) which was swapped for the term of the loan to a fixed rate of 3.15% and matures in December 2020. We realized net proceeds of approximately $49,000,000.

On December 21, 2015, we completed a $450,000,000 financing of the retail condominium of the St. Regis Hotel and the adjacent retail town house located on Fifth Avenue at 55th Street. The loan matures in December 2020, with two one-year extension options. The loan is interest only at LIBOR plus 1.80% (2.19% at December 31, 2015) for the first three years, LIBOR plus 1.90% for years four and five, and LIBOR plus 2.00% during the extension periods. We own a 74.3% controlling interest in the joint venture which owns the property.

On January 1, 2015, we redeemed all of the $500,000,000 principal amount of our outstanding 4.25% senior unsecured notes, which were scheduled to mature on April 1, 2015, at a redemption price of 100% of the principal amount plus accrued interest through December 31, 2014.

On October 30, 2015, we entered into an unsecured delayed-draw term loan facility in the maximum amount of $750,000,000. The facility matures in October 2018 with two one-year extension options. The interest rate is LIBOR plus 1.15% (1.40% at December 31, 2015) with a fee of 0.20% per annum on the unused portion. At closing, we drew $187,500,000. The facility provides that the maximum amount available is twice the amount outstanding on April 29, 2016, limited to $750,000,000, and all draws must be made by October 2017. This facility, together with the $950,000,000 development loan mentioned above, provides the funding for our 220 Central Park South development.

(Amounts in thousands)			Weighted Average
			Interest Rate at			Balance at December 31,
			December 31, 2015			2015		2014
Mortgages Payable:
	Fixed rate			4.29%	$	6,356,634	$	6,497,286
	Variable rate			2.14%		3,258,204		1,763,769
		Total		3.56%		9,614,838		8,261,055
	Deferred financing costs, net and other					(101,125)		(73,212)
		Total, net			$	9,513,713	$	8,187,843

Unsecured Debt:
	Senior unsecured notes			3.68%	$	850,000	$	1,350,000
	Deferred financing costs, net and other					(5,841)		(7,506)
		Senior unsecured notes, net				844,159		1,342,494

	Unsecured term loan			1.40%		187,500		-
	Deferred financing costs, net and other					(4,362)		-
		Unsecured term loan, net				183,138		-

	Unsecured revolving credit facilities			1.38%		550,000		-

		Total, net			$	1,577,297	$	1,342,494

The net carrying amount of properties collateralizing the mortgages payable amounted to $9.6 billion at December 31, 2015. As of December 31, 2015, the principal repayments required for the next five years and thereafter are as follows:

(Amounts in thousands)				Senior Unsecured
				Debt and Unsecured
				Revolving Credit
		Mortgages Payable		Facilities
Year Ending December 31,
2016	$	1,095,366	$	550,000
2017		411,113		-
2018		441,354		-
2019		379,122		450,000
2020		2,835,451		187,500
Thereafter		4,452,432		400,000