Investments in Unconsolidated Real Estate Entities - Summary of Financial Information for Apartment LLCs (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013	Jun. 30, 2013	Dec. 31, 2012
Real Estate Properties [Line Items]
Real estate assets, net of accumulated depreciation of $46,361 and $43,649 at June 30, 2014 and December 31, 2013, respectively	$ 2,221,738	$ 2,251,139
Total assets	2,287,789	2,381,677
Total liabilities	1,106,620	1,222,825
Members' equity	1,173,934	1,152,731	1,145,982	1,119,620
Total liabilities and equity	2,287,789	2,381,677
Unconsolidated Properties [Member]
Real Estate Properties [Line Items]
Real estate assets, net of accumulated depreciation of $46,361 and $43,649 at June 30, 2014 and December 31, 2013, respectively	208,054	209,132
Cash and other	5,943	4,978
Total assets	213,997	214,110
Mortgage notes payable	177,723	177,723
Other liabilities	3,702	2,673
Total liabilities	181,425	180,396
Members' equity	32,572	33,714
Total liabilities and equity	213,997	214,110
Company's equity investment in Apartment LLCs	$ (12,773)	$ (12,631)