Agreements and Transactions with Related Parties (Narratives) (Details) (USD $) In Millions, except Share data, unless otherwise specified	6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011
Related Party Transaction [Line Items]
Number of Shares Held by Advisor	2,962,334
Advisor Owned Percentage of Common Stock	1.20%
Percentage Of Available Cash Distribution To Advisor	10.00%
Average Estimated Minimum Lease Payment	$ 0.7
Payment Of Deferred Acquisition Fees To Advisors	9.7	8.7
Deferred offering costs	19.1
Reimbursed Offering Costs	$ 18.3
Maximum [Member]
Related Party Transaction [Line Items]
Ownership Interest In Joint Ventures	85.00%
Minimum [Member]
Related Party Transaction [Line Items]
Ownership Interest In Joint Ventures	12.00%