Unsecured Debt (Tables)

12 Months Ended

Dec. 31, 2017

Debt Disclosure [Abstract]

Schedule of unsecured debt and lines of credit

Unsecured debt consists of the following as of December 31, 2017 and 2016 ($ in thousands):

	2017			2016			Weighted Average Maturity In Years
Unsecured bonds private placement - fixed rate	$	274,427		$	314,190		3.1
Term loan - variable rate	348,545			98,189			4.1
Bonds public offering - fixed rate	2,878,737			2,834,400			6.4
Unsecured debt, net (1)	3,501,709			3,246,779
Lines of credit (2)	179,000			125,000
Total unsecured debt	$	3,680,709		$	3,371,779
Weighted average interest rate on fixed rate unsecured bonds private placement and bonds public offering	3.7		%	3.6		%
Weighted average interest rate on variable rate term loan	2.5		%	2.3		%
Weighted average interest rate on lines of credit	2.3		%	1.8		%

⁽¹⁾  Includes unamortized discount of $5.2 million and $0.1 million and unamortized debt issuance costs of $18.1 million and $18.1 million as of December 31, 2017 and 2016, respectively.

⁽²⁾  Lines of credit, related to the Company's two lines of unsecured credit aggregating $1.03 billion, excludes unamortized debt issuance costs of $3.2 million and $3.3 million as of December 31, 2017 and 2016, 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, 2017 and 2016 ($ in thousands):

	Maturity	2017		2016		Coupon Rate
Senior unsecured private placement notes	September 2017	$	—	$	40,000	4.50	%
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	$	315,000

Schedule of Long-term Debt Instruments

The following is a summary of the Company’s senior unsecured notes as of December 31, 2017 and 2016 ($ in thousands):

	Maturity	2017		2016		Coupon Rate
Senior notes	March 2017	$	—	$	300,000	5.500	%
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		—		3.625	%
		$	2,900,000	$	2,850,000

Mortgage notes payable consist of the following as of December 31, 2017 and 2016 ($ in thousands):

	2017			2016
Fixed rate mortgage notes payable	$	1,739,856		$	1,911,699
Variable rate mortgage notes payable (1)	268,561			279,782
Total mortgage notes payable (2)	$	2,008,417		$	2,191,481
Number of properties securing mortgage notes	56			61
Remaining terms	1-29 years			1-30 years
Weighted average interest rate	4.2		%	4.3		%

Schedule of Maturities of Long-term Debt

The aggregate scheduled principal payments of unsecured debt payable, excluding lines of credit, at December 31, 2017 are as follows ($ in thousands):

2018	$	—
2019	75,000
2020	—
2021(1)	500,000
2022	650,000
Thereafter	2,300,000
	$	3,525,000

⁽¹⁾  Amount does not include $179.0 million outstanding on the Company's lines of credit as of December 31, 2017, that becomes due in December 2021 in accordance with the January 2018 amendment.

The aggregate scheduled principal payments of mortgage notes payable at December 31, 2017 are as follows ($ in thousands):

2018	$	202,131
2019	560,389
2020	694,921
2021	44,846
2022	42,466
Thereafter	435,808
	$	1,980,561

⁽¹⁾  Variable rate mortgage notes payable, including $256.6 million in bonds that have been converted to variable rate through total return swap contracts, consists of multi-family 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 2.0% at December 2017 and 1.2% at December 2016) 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, $20.7 million are subject to various interest rate cap agreements that limit the maximum interest rate to such bonds.

⁽²⁾  Includes total unamortized premium of $33.2 million and $50.8 million and reduced by unamortized debt issuance costs of $5.4 million and $7.4 million as of December 31, 2017 and 2016, respectively.