Summary of Significant Accounting Policies (Additional Information 2) (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2015 USD ($) segment	Sep. 30, 2014	Dec. 31, 2014 USD ($)
Summary Of Significant Accounting Policies [Line Items]
Capital lease obligations	$ 29,600		$ 13,100
Lease financing obligations	$ 23,400
Number of operating segments | segment	1
Number of reportable segments | segment	1
Financial assets	$ 0		0
Financial liability	$ 0		0
Effective Income Tax Rate Reconciliation, Percent	28.40%	0.00%
Accounts Receivable [Member]
Summary Of Significant Accounting Policies [Line Items]
Aggregate allowance for doubtful accounts	$ 5,300		$ 3,700
Customer One [Member] | Rental Revenue [Member] | Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Percentage of total revenue	8.20%
Customer Two [Member] | Accounts Receivable [Member] | Minimum [Member]
Summary Of Significant Accounting Policies [Line Items]
Percentage of total accounts receivable	10.00%
Three Customers [Member] | Accounts Receivable [Member] | Minimum [Member]
Summary Of Significant Accounting Policies [Line Items]
Percentage of total accounts receivable	5.00%
Other Customers [Member] | Rental Revenue [Member] | Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Percentage of total revenue	5.00%
Five Customers [Member] | Accounts Receivable [Member] | Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Percentage of total accounts receivable	40.00%