Summary of Significant Accounting Policies (Additional Information 2) (Details) (USD $)	9 Months Ended
	Sep. 30, 2014 segment entity	Dec. 31, 2013
Summary Of Significant Accounting Policies [Line Items]
Outstanding liabilities for the capital leases	$ 9,042,000	$ 2,538,000
Number of operating segments	1
Number of reportable segments	1
Number of subsidiaries taxed as taxable REIT	1
Accounts Receivable [Member]
Summary Of Significant Accounting Policies [Line Items]
Aggregate allowance for doubtful accounts	$ 900,000	$ 900,000
Customer One [Member] | Rental Revenue [Member] | Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Percentage of total revenue	8.40%
Customer One [Member] | Accounts Receivable [Member] | Minimum [Member]
Summary Of Significant Accounting Policies [Line Items]
Percentage of total accounts receivable	10.00%
Other Customers [Member] | Rental Revenue [Member] | Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Percentage of total revenue	5.00%
Eight Customers [Member] | Accounts Receivable [Member] | Minimum [Member]
Summary Of Significant Accounting Policies [Line Items]
Percentage of total accounts receivable	5.00%
Eight Customers [Member] | Accounts Receivable [Member] | Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Percentage of total accounts receivable	58.00%