Leases - Supplemental balance sheet information (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Jan. 01, 2019	Dec. 31, 2018
Lease as Lessee
Operating lease right-of-use assets, net	$ 61,585	$ 62,922
Operating lease liabilities	69,346	$ 70,657
Property and equipment, at cost	2,941,254		$ 2,812,856
Accumulated amortization	(494,787)		(467,644)
Real Estate Assets, net	2,446,467		$ 2,345,212
Finance lease liabilities	47,196
Finance leased assets
Lease as Lessee
Property and equipment, at cost	48,233
Accumulated amortization	(1,477)
Real Estate Assets, net	$ 46,756