Summary of Significant Accounting Policies (Additional Information 1) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		15 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Dec. 31, 2018
Summary Of Significant Accounting Policies [Line Items]
Assets held for sale						$ 71,800
Liabilities held for sale						24,349
Amortization of the deferred financing costs	$ 1,000	$ 1,000	$ 1,957	$ 1,923	$ 1,000
Amortization of deferred leasing costs totaled	5,700	5,300	11,100	10,200
Deferred income	40,033		40,033		40,033	33,241
Amortization of deferred revenue	3,800	3,200	7,100	6,100
Company recorded equity-based compensation expense net of repurchased awards and forfeits	4,300	4,000	$ 7,600	7,500
Equity based compensation associated with the acceleration of equity awards		$ 1,700		$ 3,100
Practical Expedient, remaining term			true
Amount of the straight-line rent receivable on the balance sheets included in rents and other receivables, net	$ 32,400		$ 32,400		$ 32,400	$ 29,700
Cloud and managed services | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-01-01
Summary Of Significant Accounting Policies [Line Items]
Remaining term	3 years		3 years		3 years