Leases - Supplemental balance sheet information (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Jan. 01, 2019	Dec. 31, 2018
Lease as Lessee
Operating lease right-of-use assets	$ 59,946	$ 62,922
Operating lease liabilities	67,457	$ 70,657
Property and equipment, at cost	3,050,686		$ 2,812,856
Accumulated amortization	(523,040)		(467,644)
Real Estate Assets, net	2,527,646		$ 2,345,212
Finance lease liabilities	46,436
Finance leased assets
Lease as Lessee
Property and equipment, at cost	48,233
Accumulated amortization	(2,496)
Real Estate Assets, net	$ 45,737