Investments in Joint Ventures - 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 Equity Method Investments [Line Items]
Total Revenues	$ 84,136	$ 81,294	$ 82,098	$ 80,698	$ 81,220	$ 76,636	$ 78,946	$ 77,523	$ 328,226	$ 314,325	$ 302,668
Expenses:
Property Expenses and Other									107,390	99,907	101,281
Depreciation and Other Amortization									111,031	114,675	115,244
Interest Expense									73,558	83,506	100,127
Discontinued Operations:
Loss Attributable to Discontinued Operations									1,253	3,498	4,350
Gain on Sale of Real Estate									34,344	12,665	20,419
Net Income (Loss)									41,428	(2,519)	(9,190)
Equity in Income of Joint Ventures	17	72	27	20	1,403	28	37	91	136	1,559	980
Corporate Joint Venture [Member]
Schedule of Equity Method Investments [Line Items]
Total Revenues									3,433	3,371	3,411
Expenses:
Property Expenses and Other									1,070	1,096	1,226
Depreciation and Other Amortization									931	764	836
Interest Expense									1,532	1,633	1,643
Total Expenses									3,533	3,493	3,705
Discontinued Operations:
Loss Attributable to Discontinued Operations									(1,300)	(1,607)	(1,587)
Gain on Sale of Real Estate									513	4,974	3,137
Income from Discontinued Operations									(787)	3,367	1,550
Net Income (Loss)									(887)	3,245	1,256
Equity in Income of Joint Ventures									$ 136	$ 1,559	$ 980