Summary of Significant Accounting Policies (Additional Information 2) (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017 USD ($) subsidiary	Sep. 30, 2016 USD ($)	Sep. 30, 2017 USD ($) segment subsidiary	Sep. 30, 2016 USD ($)	Apr. 05, 2017 USD ($)	Dec. 31, 2016 USD ($)
Summary Of Significant Accounting Policies [Line Items]
Capital lease obligations	$ 10,000		$ 10,000			$ 18,100
Lease financing obligations	18,800		18,800			20,600
Net book value of assets associated with leases	$ 33,200		$ 33,200			41,500
Number of operating segments | segment			1
Number of reportable segments | segment			1
Financial assets						0
Financial liability						0
Number of subsidiaries taxed as taxable REIT | subsidiary			2
Number of REIT subsidiaries' deferred tax assets due to U.S. NOL carryforwards | subsidiary	1		1
Effective tax rate			46.40%	48.90%
Decrease in fair value of interest rate swaps	$ (286)		$ (1,785)
Interest Rate Swap
Summary Of Significant Accounting Policies [Line Items]
Derivative instruments, notional amount					$ 400,000
Decrease in fair value of interest rate swaps		$ 0		$ 0
Interest Rate Swap | Term Loan
Summary Of Significant Accounting Policies [Line Items]
Debt Instrument Face Amount					400,000
Interest Rate Swap | Term Loan Maturing December 17,2021
Summary Of Significant Accounting Policies [Line Items]
Derivative instruments, notional amount					200,000
Interest Rate Swap | Term Loan Maturing April 27, 2022
Summary Of Significant Accounting Policies [Line Items]
Derivative instruments, notional amount					$ 200,000
Accounts Receivable
Summary Of Significant Accounting Policies [Line Items]
Aggregate allowance for doubtful accounts	$ 5,700		$ 5,700			$ 4,200
Customer One | Rental Revenue
Summary Of Significant Accounting Policies [Line Items]
Percentage of total revenue			12.50%
No Other Customers | Rental Revenue | Minimum
Summary Of Significant Accounting Policies [Line Items]
Percentage of total revenue			5.00%
Five Customers | Accounts Receivable
Summary Of Significant Accounting Policies [Line Items]
Percentage of total accounts receivable	44.00%		44.00%
Five Customers | Accounts Receivable | Minimum
Summary Of Significant Accounting Policies [Line Items]
Percentage of total accounts receivable	5.00%		5.00%
Two Customers [Member] | Accounts Receivable | Minimum
Summary Of Significant Accounting Policies [Line Items]
Percentage of total accounts receivable	10.00%		10.00%
Carpathia Hosting, Inc.
Summary Of Significant Accounting Policies [Line Items]
Lease financing obligations	$ 18,800		$ 18,800