Equity (Details) (USD $)	12 Months Ended			0 Months Ended	12 Months Ended	1 Months Ended		12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Feb. 27, 2013 Archstone	Dec. 31, 2013 Archstone	May 31, 2013 Archstone Lehman Brothers Holdings, Inc	Aug. 31, 2012 CEP III	Dec. 31, 2013 CEP III
Equity
Common stock, shares authorized	280,000,000	140,000,000
Preferred stock, shares authorized	50,000,000	50,000,000
Common stock shares issued in connection with stock options exercised	44,241
Common stock shares issued through dividend reinvestment plan	2,002	2,331	3,343
Common stock shares issued in connection with stock grants	123,977	96,592	511,817
Number of shares of stock grants withheld	48,310	121,351	129,762
Restricted common stock shares forfeited	7,653
Number of shares issued				14,889,706	14,889,706
Shares issued under Employee Stock Purchase Plan	9,260
Shares sold by Lehman						$ 7,870,000
Common stock shares issued								0
Maximum value of shares of common stock that can be sold (in dollars)							750,000,000
Period during which common stock can be sold							36 months
Percentage of compensation received by sales agent								1.50%
Value of additional shares authorized for issuance								$ 646,274,000