Unsecured Revolving Credit Facility

On October 17, 2017, we extended one of our two $1.25 billion unsecured revolving credit facilities from November 2018 to January 2022 with two six-month extension options. The interest rate on the extended facility was lowered from LIBOR plus 1.05% to LIBOR plus 1.00%. The interest rate and facility fees are the same as our other $1.25 billion unsecured revolving credit facility, which matures in February 2021 with two six-month extension options.

Senior Unsecured Notes

On December 27, 2017, we completed a public offering of $450,000,000 3.50% senior unsecured notes due January 15, 2025. The interest rate on the senior unsecured notes will be payable semi-annually on January 15 and July 15, commencing July 15, 2018. The notes were sold at 99.596% of their face amount to yield 3.565%.

On December 27, 2017, we redeemed all of the $450,000,000 principal amount of our outstanding 2.50% senior unsecured notes which were scheduled to mature on June 30, 2019, at a redemption price of approximately 100.71% of the principal amount plus accrued interest through the date of redemption. In connection therewith, we expensed $4,836,000 of debt prepayment costs and wrote-off unamortized deferred financing costs which are included in "interest and debt expense" on our consolidated statements of income.


8.	Debt – continued

The following is a summary of our debt:



(Amounts in thousands)	Weighted Average Interest Rate at December 31, 2017	Balance at December 31,
	Weighted Average Interest Rate at December 31, 2017	2017			2016
Mortgages Payable:
Fixed rate	3.65%	$	5,461,706		$	5,479,547
Variable rate	3.33%	2,742,133			2,727,133
Total	3.54%	8,203,839			8,206,680
Deferred financing costs, net and other		(66,700		)	(93,432		)
Total, net		$	8,137,139		$	8,113,248
Unsecured Debt:
Senior unsecured notes	4.21%	$	850,000		$	850,000
Deferred financing costs, net and other		(6,386		)	(4,423		)
Senior unsecured notes, net		843,614			845,577

Unsecured term loan	2.68%	750,000			375,000
Deferred financing costs, net and other		(1,266		)	(2,785		)
Unsecured term loan, net		748,734			372,215

Unsecured revolving credit facilities	—%	—			115,630

Total, net		$	1,592,348		$	1,333,422

The net carrying amount of properties collateralizing the mortgages payable amounted to $9.8 billion at December 31, 2017. As of December 31, 2017, the principal repayments required for the next five years and thereafter are as follows:



(Amounts in thousands)	Mortgages Payable		Senior Unsecured Debt and Unsecured Resolving Credit Unsecured Facilities
Year Ended December 31,
2018	$	2,009,030	$	750,000
2019	973,294		—
2020	1,867,567		—
2021	1,613,948		—
2022	950,000		400,000
Thereafter	790,000		450,000