Debt (Lease Narrative) (Details) $ in Millions	3 Months Ended
	Mar. 31, 2018 USD ($) agreement facility	Dec. 31, 2017 USD ($)
Capital Leased Assets [Line Items]
Lease financing obligations	$ 0.7	$ 0.9
Carpathia Hosting, Inc.
Capital Leased Assets [Line Items]
Capital lease, lease financing obligations and mortgage notes payable	5.7
Capital lease and lease financing obligations assumed	$ 4.3
Number of lease agreements | agreement	2
The number of data centers with lease agreements and lease financing agreements | facility	1
Outstanding financing agreement	$ 0.7
Lease financing expiration date	Feb. 01, 2019
Carpathia Hosting, Inc. | Tenant Improvement Allowance [Member]
Capital Leased Assets [Line Items]
Lease financing obligations	$ 4.8
Minimum | Carpathia Hosting, Inc.
Capital Leased Assets [Line Items]
Lease expiration year	2018
Monthly lease payment	$ 0.2
Maximum | Carpathia Hosting, Inc.
Capital Leased Assets [Line Items]
Lease expiration year	2019
Monthly lease payment	$ 0.5
Lease financing monthly principal and interest payment	$ 0.1