XML 52 R30.htm IDEA: XBRL DOCUMENT

Summary of Significant Accounting Policies (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Investments in Real Estate
Capitalized interest costs	$ 1.3us-gaap_InterestCostsCapitalized	$ 1.2us-gaap_InterestCostsCapitalized
Depreciation expense	$ 18.0us-gaap_Depreciation	$ 15.1us-gaap_Depreciation
Building \| Minimum
Investments in Real Estate
Useful lives	27 years
Building \| Maximum
Investments in Real Estate
Useful lives	40 years
Building Improvements \| Minimum
Investments in Real Estate
Useful lives	1 year
Building Improvements \| Maximum
Investments in Real Estate
Useful lives	10 years