Leases - Narrative (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2019 USD ($) building	Mar. 31, 2018 USD ($)
Lessee, Lease, Description [Line Items]
Pricing period	30 years
Number of buildings subleased | building	7
Rental and other revenues related to operating lease payments	$ 381,084	$ 343,369
Rental and other revenues related to operating lease payments, variable leases	$ 47,350
Minimum
Lessee, Lease, Description [Line Items]
Lease term extension period	1 year
Maximum
Lessee, Lease, Description [Line Items]
Lease term extension period	25 years