3. Notes Payable, Unsecured Notes and Credit Facility

The Company's mortgage notes payable, unsecured notes, and Credit Facility, as defined below, as of December 31, 2013 and December 31, 2012 are summarized below (dollars in thousands). The following amounts and discussion do not include the mortgage notes related to the communities classified as held for sale, if any, as of December 31, 2013 and 2012, as shown in the Consolidated Balance Sheets (dollars in thousands) (see Note 7, "Real Estate Disposition Activities").

	12-31-13		12-31-12

Fixed rate unsecured notes(1)	$	2,600,000	$	1,950,000
Fixed rate mortgage notes payable—conventional and tax-exempt(2)		2,418,389		1,427,133
Variable rate mortgage notes payable—conventional and tax-exempt		1,011,609		476,935

Total notes payable and unsecured notes		6,029,998		3,854,068
Credit Facility		—		—

Total mortgage notes payable, unsecured notes and Credit Facility	$	6,029,998	$	3,854,068

(1): Balances at December 31, 2013 and December 31, 2012 exclude $5,291 and $4,202 of debt discount, respectively, as reflected in unsecured notes, net on the Company's Consolidated Balance Sheets.
(2): Balances at December 31, 2013 and December 31, 2012 exclude $120,684 and $1,167 of debt premium, respectively, as reflected in mortgage notes payable on the Company's Consolidated Balance Sheets.

The following debt activity occurred during the year ended December 31, 2013:

•

In February 2013, as a portion of the consideration for the Archstone Acquisition, the Company assumed $3,512,202,000 consolidated principal amount of Archstone's existing secured indebtedness, repaying $1,477,720,000 principal amount of the indebtedness assumed concurrent with the closing of the Archstone Acquisition.

•

In March 2013, the Company repaid $100,000,000 of its 4.95% unsecured notes in accordance with the scheduled maturity.

•

In April 2013, the Company obtained a 3.06% fixed rate, secured mortgage loan in the amount of $15,000,000 that matures in April 2018.

•

In April 2013, the Company repaid a 4.69% fixed rate, secured mortgage note in the amount of $170,125,000 pursuant to its scheduled maturity date.

•

In May 2013, the Company repaid a $5,393,000 fixed rate secured mortgage note with an interest rate of 5.55% at par and without penalty in advance of its July 2028 scheduled maturity date.

•

In May 2013, the Company obtained a 3.08% fixed rate secured mortgage loan that matures in June 2020 in the amount of $56,210,000, in association with the refinancing of an existing $47,000,000 variable rate secured mortgage note. The refinancing was necessitated by the secured community-specific tax protection obligation assumed through certain of the preferred interests the Company assumed as part of the Archstone Acquisition.

•

In May 2013, the Company repaid a $52,806,000 fixed rate secured mortgage note with an interest rate of 5.24% pursuant to its scheduled maturity date.

•

In September 2013, the Company issued $400,000,000 principal amount of unsecured notes in a public offering under its existing shelf registration statement for net proceeds of approximately $396,212,000. The notes mature in October 2020 and were issued at a 3.63% interest rate. The notes have an effective interest rate of 3.79% including the effect of offering costs.

•

In December 2013, the Company issued $350,000,000 principal amount of unsecured notes in a public offering under its existing shelf registration statement for net proceeds of approximately $346,934,000. The notes mature in December 2023 and were issued at a 4.20% interest rate. The notes have an effective interest rate of 4.30% including the effect of offering costs.

•

In December 2013, the Company repaid a $150,000,000 fixed rate secured mortgage note with an interest rate of 5.66%, a $110,600,000 fixed rate secured mortgage note with an interest rate of 5.48%, and a $41,439,000 fixed rate secured mortgage note with an interest rate of 4.75%, in advance of their 2015 maturity dates, and incurred a charge for prepayment penalties and the write-off of deferred fees of $14,921,000.

The Company has a $1,300,000,000 revolving variable rate unsecured credit facility with a syndicate of banks (the "Credit Facility") which matures in April 2017. The Company has the option to extend the maturity by up to one year under two, six month extension options for an aggregate fee of $1,950,000. The Credit Facility bears interest at varying levels based on the London Interbank Offered Rate ("LIBOR"), rating levels achieved on the unsecured notes and on a maturity schedule selected by the Company. The current stated pricing is LIBOR plus 1.05% (1.22% at December 31, 2013), assuming a one month borrowing rate. The annual facility fee is approximately $1,950,000 based on the $1,300,000,000 facility size and based on the Company's current credit rating.

The Company had no borrowings outstanding under the Credit Facility and had $65,018,000 and $44,833,000 outstanding in letters of credit that reduced the borrowing capacity as of December 31, 2013 and December 31, 2012, respectively.

In the aggregate, secured notes payable mature at various dates from November 2015 through July 2066, and are secured by certain apartment communities and improved land parcels (with a net carrying value of $4,469,421,000, excluding communities classified as held for sale, as of December 31, 2013).

As of December 31, 2013, the Company has guaranteed approximately $309,358,000 of mortgage notes payable held by wholly-owned subsidiaries; all such mortgage notes payable are consolidated for financial reporting purposes. The weighted average interest rate of the Company's fixed rate mortgage notes payable (conventional and tax-exempt) was 3.4% and 5.8% at December 31, 2013 and December 31, 2012, respectively. The weighted average interest rate of the Company's variable rate mortgage notes payable and its Credit Facility, including the effect of certain financing related fees, was 1.8% and 2.7% at December 31, 2013 and December 31, 2012, respectively.

Scheduled payments and maturities of mortgage notes payable and unsecured notes outstanding at December 31, 2013 are as follows (dollars in thousands):

Year	Secured notes payments		Secured notes maturities		Unsecured notes maturities

2014	$	16,986	$	—	$	150,000	5.375	%
2015		16,722		603,044		—	—
2016		17,951		16,255		250,000	5.750	%
2017		19,033		710,491		250,000	5.700	%
2018		18,398		77,432		—	—
2019		7,125		610,811		—	—
2020		6,190		50,824		250,000	6.100	%
						400,000	3.625	%
2021		5,965		27,844		250,000	3.950	%
2022		6,350		—		450,000	2.950	%
2023		6,744		—		350,000	4.300	%
						250,000	3.000	%
Thereafter		85,771		1,126,062		—	—	%
	$	207,235	$	3,222,763	$	2,600,000

The Company's unsecured notes are redeemable at our option, in whole or in part, generally at a redemption price equal to the greater of (i) 100% of their principal amount or (ii) the sum of the present value of the remaining scheduled payments of principal and interest discounted at a rate equal to the yield on U.S. Treasury securities with a comparable maturity plus a spread between 25 and 45 basis points depending on the specific series of unsecured note, plus accrued and unpaid interest to the redemption date. The indenture under which the Company's unsecured notes were issued contains limitations on the amount of debt the Company can incur or the amount of assets that can be used to secure other financing transactions, and other customary financial and other covenants, with which the Company was in compliance at December 31, 2013.