Leases - Lease Obligations (Details) $ in Thousands	Jun. 30, 2018 USD ($)
Minimum Rental Revenues
2018 (Remainder)	$ 84,214
2019	173,736
2020	159,982
2021	141,411
2022	123,077
Thereafter	545,937
Total	1,228,357
Minimum Rental Payments
2018 (Remainder)	2,394
2019	4,770
2020	4,566
2021	4,349
2022	4,399
Thereafter	184,624
Total	$ 205,102