Real Estate Activity (Consolidated Joint Venture) - Additional Information (Detail) $ in Thousands	Jun. 30, 2016 USD ($) Apartment	Dec. 31, 2015 USD ($)	Jun. 30, 2015 USD ($)	Dec. 31, 2014 USD ($)
Real Estate Properties [Line Items]
Number of units in real estate property | Apartment	24,162
Construction in progress	$ 215,427	$ 151,270
Cash and cash equivalents	3,875	28,611	$ 119,057	$ 140,512
Accounts payable, accrued expenses and other	$ 89,450	$ 74,855
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	$ 29,064
Cash and cash equivalents	262
Accounts payable, accrued expenses and other	2,214
Noncontrolling equity interest	$ 2,008