Real Estate Activities (Consolidated Joint Venture) - Additional Information (Detail) $ in Thousands	Dec. 31, 2015 USD ($) Apartment	Aug. 31, 2015 Apartment	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)	Dec. 31, 2012 USD ($)
Real Estate Properties [Line Items]
Number of units in real estate property | Apartment	24,162
Construction in progress	$ 151,270		$ 86,971
Cash and cash equivalents	28,611		140,512	$ 82,110	$ 118,698
Accounts payable, accrued expenses and other	74,855		$ 70,616
Consolidated Joint Venture [Member] | Denver, Colorado [Member]
Real Estate Properties [Line Items]
Number of units in real estate property | Apartment		358
Equity interest ownership percentage		92.50%
Construction in progress	21,367
Cash and cash equivalents	100
Accounts payable, accrued expenses and other	982
Noncontrolling equity interest	$ 1,545