Investment in and Advances to Unconsolidated Affiliates (Details) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Income Statements:
Revenues	$ 24,779,000	$ 31,714,000	$ 49,996,000	$ 67,302,000
Expenses:
Rental property and other expenses	10,774,000	15,632,000	22,771,000	32,799,000
Depreciation and amortization	6,295,000	7,778,000	12,911,000	17,378,000
Interest expense	5,858,000	7,233,000	11,865,000	15,798,000
Total expenses	22,927,000	30,643,000	47,547,000	65,975,000
Net income	1,852,000	1,071,000	2,449,000	1,327,000
Our share of:
Depreciation and amortization of real estate assets	2,033,000	2,737,000	4,126,000	6,078,000
Interest expense	2,033,000	2,755,000	4,194,000	6,178,000
Net income	749,000	308,000	1,670,000	520,000
Our share of net income	749,000	308,000	1,670,000	520,000
Purchase accounting and management, leasing and other fees adjustments	604,000	580,000	1,150,000	1,163,000
Equity in earnings of unconsolidated affiliates	1,353,000	888,000	2,820,000	1,683,000
Percentage of equity interest in joint ventures, minimum	10.00%		10.00%
Percentage of equity interest in joint ventures, maximum	50.00%		50.00%
Number of joint ventures with debt investment	1		1
Investments in and Advances to Affiliates [Line Items]
Advances to Affiliates loan amount	$ 38,300,000
Duration of loan, in years	1
Current interest rate	LIBOR plus 500 basis points
Interest rate reduction amount	50 basis points