Summary of Significant Accounting Policies (Impairment to Equity-based Compensation ) (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020 USD ($)	Jun. 30, 2019 USD ($)	Jun. 30, 2020 USD ($) item	Jun. 30, 2019 USD ($)	Dec. 31, 2019 USD ($)	Nov. 08, 2017 USD ($)	Jul. 23, 2014
Summary Of Significant Accounting Policies [Line Items]
Impairment losses	$ 0	$ 0	$ 0	$ 0
Number of Reporting Units | item			1
Amortization of the deferred financing costs		1,000	$ 1,978	1,957
Amortization of deferred leasing costs	6,300	5,700	12,500	11,100
Amount of the straight-line rent receivable on the balance sheets included in rents and other receivables, net	47,600		$ 47,600		$ 38,700
Practical Expedient, remaining term			true
Aggregate allowance for doubtful accounts	6,500		$ 6,500		2,300
Deferred income	43,461		43,461		$ 39,169
Amortization of deferred revenue	4,500	3,800	8,400	7,100
Company recorded equity-based compensation expense net of repurchased awards and forfeits	$ 6,100	$ 4,300	$ 11,000	$ 7,600
Cloud and managed services | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-04-01
Summary Of Significant Accounting Policies [Line Items]
Remaining term	3 years		3 years
Senior Notes
Summary Of Significant Accounting Policies [Line Items]
Debt Instrument Face Amount						$ 400,000
Interest rate	4.75%		4.75%			4.75%	5.875%