Discontinued Operations (Narrative) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013 property	Dec. 31, 2012 property	Feb. 11, 2015 property	Dec. 31, 2014 property
Discontinued Operations [Line Items]
Number of properties			11	126
Northern New Jersey Or New York City [Member]
Discontinued Operations [Line Items]
Number of properties				41
Northern New Jersey Or New York City [Member] | Discontinued Operations [Member]
Discontinued Operations [Line Items]
Number of properties	1
Sales price of property sold	$ 19.0
Gain on sale of property	2.8
Los Angeles [Member] | Discontinued Operations [Member]
Discontinued Operations [Line Items]
Number of properties		1
Sales price of property sold		17.0
Gain on sale of property		$ 4.0