SUBSEQUENT EVENT (Details) (USD $)				0 Months Ended	3 Months Ended	0 Months Ended
	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2013 Head Acquisition, LP ("Head")	Oct. 30, 2013 Subsequent event Head Acquisition, LP ("Head")	Dec. 31, 2013 Subsequent event Head Acquisition, LP ("Head")	Oct. 04, 2013 Subsequent event Joint venture partner item acre sqft	Oct. 02, 2013 Subsequent event 6.875% Senior Notes Due 2021	Oct. 24, 2013 Subsequent event Construction loan Outlet at Riverwalk item
Subsequent events
Aggregate principal amount of debt issued							$ 750,000,000
Interest rate (as a percent)							6.875%
Maximum percentage of Notes that can be redeemed using proceeds from equity offerings at any time prior to October 1, 2016							35.00%
Number of units in Class A apartment building to be constructed						437
Area of real estate property to be constructed (in square feet)						31,000
Area of land contributed to the joint venture (in acres)						5
Book value of the land contributed to joint venture						4,000,000
Transaction value of the land contributed to joint venture						23,400,000
Transaction value, per constructed unit of land contributed to joint venture						53,500
Mortgages, notes and loans payable	765,980,000	688,312,000						64,400,000
Variable rate basis								one-month LIBOR
Interest rate margin (as a percent)								2.75%
Number of extension options								2
Option to extend, term								1 year
Net cash proceeds				13,300,000
Gain from sale					8,500,000
Deferred tax asset due to book/tax basis differences			$ 76,400,000
Percentage of principal amount at which Notes can be redeemed							106.875%