Notes Payable and Unsecured Credit Facilities (Tables)

12 Months Ended

Dec. 31, 2012

Debt Disclosure [Abstract]

Schedule of Long-term Debt Instruments [Table Text Block]

The Company’s outstanding debt at December 31, 2012 and 2011 consists of the following (in thousands):

		2012	2011
Notes payable:
Fixed rate mortgage loans	$	461,914	439,880
Variable rate mortgage loans		12,041	12,665
Fixed rate unsecured loans		1,297,936	1,489,895
Total notes payable		1,771,891	1,942,440
Unsecured credit facilities		170,000	40,000
Total	$	1,941,891	1,982,440

Schedule of Maturities of Long-term Debt [Table Text Block]

As of December 31, 2012, scheduled principal payments and maturities on notes payable were as follows (in thousands):

Scheduled Principal Payments and Maturities by Year:		Scheduled Principal Payments	Mortgage Loan Maturities	Unsecured Maturities (1)		Total
2013	$	7,872	16,319	—		24,191
2014		7,383	26,999	150,000		184,382
2015		5,746	62,435	350,000		418,181
2016		5,487	14,161	170,000		189,648
2017		4,584	84,375	400,000		488,959
Beyond 5 Years		20,021	212,743	400,000		632,764
Unamortized debt premiums (discounts), net		—	5,830	(2,064	)	3,766
Total	$	51,093	422,862	1,467,936		1,941,891
(1) Includes unsecured public debt and unsecured credit facilities balances outstanding at December 31, 2012.