Investments in and Advances to Other Real Estate Partnerships - Condensed Combined Statements of Operations (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Schedule Of Condensed Consolidating Statement Of Operations [Line Items]
Total Revenues	$ 73,960	$ 71,454	$ 72,376	$ 71,146	$ 71,525	$ 67,313	$ 68,909	$ 67,696	$ 288,936	$ 275,443	$ 263,826
Property Expenses									(95,104)	(88,605)	(89,772)
Impairment of Real Estate									(2,652)	(1,101)	2,079
Depreciation and amortization									(98,824)	(100,683)	(102,485)
Interest Income									2,438	2,940	3,990
Interest Expense									(68,857)	(77,794)	(95,103)
Amortization of Deferred Financing Costs									(3,038)	(3,252)	(3,785)
Loss from Retirement of Debt									(6,423)	(9,684)	(5,299)
Income (Loss) from Continuing Operations	2,856	4,337	(1,193)	979	(3,466)	(370)	(13,374)	(5,123)	6,979	(22,333)	(31,336)
Discontinued Operations:
Income Attributable to Discontinued Operations									977	3,380	3,888
(Loss) Gain on Sale of Real Estate									32,657	12,758	18,814
Income from Discontinued Operations	19,237	4,180	12,586	(2,369)	1,095	5,786	3,030	6,227	33,634	16,138	21,456
Gain on Sale of Real Estate									1,030	3,777	1,370
Net Income (Loss)	22,430	8,738	11,393	(1,128)	(2,371)	9,193	(10,344)	1,104	41,433	(2,418)	(8,962)
Other Real Estate Partnerships
Schedule Of Condensed Consolidating Statement Of Operations [Line Items]
Total Revenues									39,290	38,882	39,001
Property Expenses									(12,286)	(11,302)	(11,509)
Impairment of Real Estate									0	172	582
Depreciation and amortization									(12,207)	(13,992)	(12,759)
Interest Income									4,999	7,776	11,697
Interest Expense									(4,701)	(5,712)	(5,024)
Amortization of Deferred Financing Costs									(187)	(208)	(178)
Loss from Retirement of Debt									(214)	0	(160)
Income (Loss) from Continuing Operations									14,694	15,616	21,650
Discontinued Operations:
Income Attributable to Discontinued Operations									276	118	462
(Loss) Gain on Sale of Real Estate									1,687	(93)	1,605
Income from Discontinued Operations									1,963	25	2,067
Gain on Sale of Real Estate									70	0	0
Net Income (Loss)									$ 16,727	$ 15,641	$ 23,717