Revenue Recognition - Disaggregation of Revenue (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	$ 245.9	$ 225.0
Total lease revenue
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	238.8	216.9
Colocation (Minimum lease payments)
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	204.0	188.4
Metered power reimbursements (Variable lease payments)
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	34.8	28.5
Total revenue from contracts with customers
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	7.1	8.1
Equipment sales and services
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	2.5	3.9
Other revenue
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	$ 4.6	$ 4.2