Summary of Significant Accounting Policies (Goodwill Reconciliation) (Details) - USD ($) $ in Thousands	12 Months Ended							36 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Goodwill [Roll Forward]
Goodwill	$ 104,786
Goodwill	98,918	$ 104,786
Restatement Adjustment [Member]
Goodwill [Roll Forward]
Goodwill	104,786	148,759	$ 149,957	$ 155,704	$ 160,007	$ 177,540	$ 180,097	$ 0
Purchase of property management companies results in Goodwill (April 2007)								180,097
Goodwill allocated to impairment loss on real estate assets	(5,152)	(38,554)	(1,198)	(4,412)	(4,303)	(17,533)		0
Goodwill allocated to impairment loss on real estate assets	(716)	(3,132)		(1,335)			(2,557)
Goodwill allocated to other assets held for sale		(2,287)
Goodwill	$ 98,918	$ 104,786	$ 148,759	$ 149,957	$ 155,704	$ 160,007	$ 177,540	$ 180,097