Commitments and Contingencies (Details Textual) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014 USD ($)	Dec. 31, 2014 CAD	Dec. 31, 2013 USD ($)	Dec. 31, 2012 USD ($)	Dec. 31, 2014 HSRE I [Member] USD ($)	Dec. 31, 2014 HSRE V [Member]	Dec. 31, 2014 HSRE IX [Member]	Dec. 31, 2014 CSH Montreal [Member] USD ($)	Dec. 31, 2014 CSH Montreal [Member] CAD	Dec. 31, 2014 HSRE V and HSRE VI and HSRE X [Member]
Lease Obligations Expiration Year	2023	2023
Ground Leases Obligations	$ 0.4
Ground Leases Obligations Expiration Year	2081	2081
Description For Guarantees One					up to 100% of $32.5 million of debt through May 2015
Description For Guarantees Two										up to 50% of $144.1 million of debt with varying maturity dates from March 2015 through September 2018
Description For Guarantees Three							up to 25% of $90.2 million of debt maturing in July 2016
Description For Guarantees Four						$13.3 million relates to a property that was sold on January 30, 2015
Guarantees Investment	6.2
Guarantees Underlying Debt	44.0	50.9
Held In Escrow Amount					3.0
Capital Lease Obligations	1.3
Operating Leases, Rent Expense, Net	1.2		0.9	0.6
Guarantees, Fair Value Disclosure	9.4				3.2
Accrued Liabilities and Other Liabilities	4.5
Line of Credit Facility, Average Outstanding Amount								88.0	101.8
Notes Payable								$ 96.8	112.0