Summary of Significant Accounting Policies (Additional Information 2) (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2017 USD ($) segment	Mar. 31, 2016	Dec. 31, 2016 USD ($)
Summary Of Significant Accounting Policies [Line Items]
Capital lease obligations	$ 15,400		$ 18,100
Lease financing obligations	20,000		20,600
Net book value of assets associated with leases	$ 38,700		41,500
Number of operating segments | segment	1
Number of reportable segments | segment	1
Financial assets	$ 0		0
Financial liability	$ 0		0
Effective tax rate	39.70%	37.40%
Accounts Receivable [Member]
Summary Of Significant Accounting Policies [Line Items]
Aggregate allowance for doubtful accounts	$ 4,500		$ 4,200
Customer One [Member] | Rental Revenue [Member] | Maximum
Summary Of Significant Accounting Policies [Line Items]
Percentage of total revenue	13.20%
Three Customers [Member] | Accounts Receivable [Member] | Minimum
Summary Of Significant Accounting Policies [Line Items]
Percentage of total accounts receivable	10.00%
Other Customers [Member] | Rental Revenue [Member] | Maximum
Summary Of Significant Accounting Policies [Line Items]
Percentage of total revenue	5.00%
Six Customers [Member] | Accounts Receivable [Member] | Minimum
Summary Of Significant Accounting Policies [Line Items]
Percentage of total accounts receivable	5.00%
Six Customers [Member] | Accounts Receivable [Member] | Maximum
Summary Of Significant Accounting Policies [Line Items]
Percentage of total accounts receivable	85.00%
Carpathia Hosting, Inc.
Summary Of Significant Accounting Policies [Line Items]
Lease financing obligations	$ 20,000