Property Dispositions (Details) (USD $) In Millions, unless otherwise specified			3 Months Ended
	Mar. 31, 2014 property	Dec. 31, 2013 property	Mar. 31, 2014 2014 Property Dispositions [Member] property
Long Lived Assets Held-for-sale [Line Items]
Number of single tenant properties sold			16
Number of multi tenant properties sold			1
Discontinued operations, gross sales price			$ 60.3
Number of real estate properties, held for sale	0	1