Subsequent Events (Details) (USD $)	9 Months Ended		0 Months Ended	1 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Oct. 17, 2013 Subsequent Event [Member]	Oct. 29, 2013 Subsequent Event [Member] acre
Subsequent Event [Line Items]
Aggregate dividends, distributions, and dividend equivalents paid to common stockholders and common unitholders	$ 82,152,000	$ 70,517,000	$ 29,800,000
Area of land				2.0
Payments to acquire land				$ 17,000,000