Real Estate Investments (Development Activities) (Details) $ in Millions	9 Months Ended
	Sep. 30, 2016 USD ($) development_project	Sep. 30, 2015 USD ($)	Dec. 31, 2015 USD ($)
Real Estate [Abstract]
Land and construction in progress	$ 8.4		$ 20.0
Number of development projects to complete | development_project	37
Number of development projects completed | development_project	36
Aggregate cost to date	$ 52.3
Capitalized interest expense	$ 0.2	$ 1.0
Number of remaining projects to be completed | development_project	1
Estimated completion period for remaining projects	6 months
Invested to date	$ 1.1
Estimated remaining investment	0.7
Total investment	$ 1.8
Number of development projects completed and placed into service | development_project	5
Aggregate cost of projects completed placed into service	$ 14.8