Unsecured Debt (Tables)

12 Months Ended

Dec. 31, 2018

Debt Disclosure [Abstract]

Schedule of unsecured debt and lines of credit

Unsecured debt consists of the following as of December 31, 2018 and 2017 ($ in thousands):

	2018			2017			Weighted Average Maturity In Years
Unsecured bonds private placement - fixed rate	$	274,624		$	274,427		2.1
Term loan - variable rate	348,813			348,545			3.1
Bonds public offering - fixed rate	3,175,879			2,878,737			7.7
Unsecured debt, net (1)	3,799,316			3,501,709
Lines of credit (2)	—			179,000
Total unsecured debt	$	3,799,316		$	3,680,709
Weighted average interest rate on fixed rate unsecured bonds private placement and bonds public offering	3.9		%	3.7		%
Weighted average interest rate on variable rate term loan	3.0		%	2.5		%
Weighted average interest rate on lines of credit	3.2		%	2.3		%

⁽¹⁾  Includes unamortized discount, net of premiums, of $7.1 million and $5.2 million and unamortized debt issuance costs of $18.5 million and $18.1 million as of December 31, 2018 and 2017, respectively.

⁽²⁾  Lines of credit, related to the Company's two lines of unsecured credit aggregating $1.24 billion, excludes unamortized debt issuance costs of $3.9 million and $3.2 million as of December 31, 2018 and 2017, respectively. These debt issuance costs are included in prepaid expenses and other assets on the consolidated balance sheets.

Summary of unsecured private placement bonds

The following is a summary of the Company’s unsecured private placement bonds as of December 31, 2018 and 2017 ($ in thousands):

	Maturity	2018		2017		Coupon Rate
Senior unsecured private placement notes	December 2019	75,000		75,000		4.92	%
Senior unsecured private placement notes	April 2021	100,000		100,000		4.27	%
Senior unsecured private placement notes	June 2021	50,000		50,000		4.30	%
Senior unsecured private placement notes	August 2021	50,000		50,000		4.37	%
		$	275,000	$	275,000

Schedule of Long-term Debt Instruments

The following is a summary of the Company’s senior unsecured notes as of December 31, 2018 and 2017 ($ in thousands):

	Maturity	2018		2017		Coupon Rate
Senior notes	March 2021	$	300,000	$	300,000	5.200	%
Senior notes	August 2022	300,000		300,000		3.625	%
Senior notes	January 2023	300,000		300,000		3.375	%
Senior notes	May 2023	300,000		300,000		3.250	%
Senior notes	May 2024	400,000		400,000		3.875	%
Senior notes	April 2025	500,000		500,000		3.500	%
Senior notes	April 2026	450,000		450,000		3.375	%
Senior notes	May 2027	350,000		350,000		3.625	%
Senior notes	March 2048	300,000		—		4.500	%
		$	3,200,000	$	2,900,000

Mortgage notes payable consist of the following as of December 31, 2018 and 2017 ($ in thousands):

	2018			2017
Fixed rate mortgage notes payable	$	1,538,488		$	1,739,856
Variable rate mortgage notes payable (1)	268,138			268,561
Total mortgage notes payable (2)	$	1,806,626		$	2,008,417
Number of properties securing mortgage notes	50			56
Remaining terms	1-28 years			1-29 years
Weighted average interest rate	4.3		%	4.2		%

Schedule of Maturities of Long-term Debt

The aggregate scheduled principal payments of unsecured debt payable, excluding lines of credit, at December 31, 2018 are as follows ($ in thousands):

2019	$	75,000
2020	—
2021	500,000
2022	650,000
2023	600,000
Thereafter	2,000,000
	$	3,825,000

The aggregate scheduled principal payments of mortgage notes payable at December 31, 2018 are as follows ($ in thousands):

2019	$	515,658
2020	693,723
2021	43,604
2022	41,178
2023	852
Thereafter	500,880
	$	1,795,895

⁽¹⁾  Variable rate mortgage notes payable, including $256.0 million in bonds that have been converted to variable rate through total return swap contracts, consists of multifamily housing mortgage revenue bonds secured by deeds of trust on rental properties and guaranteed by collateral pledge agreements, payable monthly at a variable rate as defined in the Loan Agreement (approximately 2.5% at December 2018 and 2.0% at December 2017) including credit enhancement and underwriting fees. Among the terms imposed on the properties, which are security for the bonds, is a requirement that 20% of the apartment homes are subject to tenant income criteria. Principal balances are due in full at various maturity dates from May 2025 through December 2046. Of these bonds, $9.9 million are subject to various interest rate cap agreements that limit the maximum interest rate to such bonds.

⁽²⁾  Includes total unamortized premium, net of discounts, of $14.9 million and $33.2 million and reduced by unamortized debt issuance costs of $4.2 million and $5.4 million as of December 31, 2018 and 2017, respectively.