Leases - Other Lease Disclosures (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Lessee
Operating cash flows from finance leases				$ 5,213
Operating cash flows from operating leases			$ 1,840
Financing cash flows from finance leases				2,261
Right-of-use assets obtained in exchange for new operating lease liabilities			6,983
Finance Leases
2019	$ 14,949		14,949
2020	14,949		14,949
2021	14,949		14,949
2022	14,949		14,949
2023	14,949		14,949
Thereafter	70,483		70,483
Total lease payments	145,228		145,228
Less: imputed interest	(58,036)		(58,036)
Total finance lease liabilities	87,192		87,192		$ 87,192
Operating Leases
2019	1,870		1,870
2020	1,402		1,402
2021	798		798
2022	608		608
2023	386		386
Thereafter	1,157		1,157
Total lease payments	6,221		6,221
Less: imputed interest	(957)		(957)
Total operating lease liabilities	5,264		5,264
Total finance and operating lease liabilities
2019	16,819		16,819
2020	16,351		16,351
2021	15,747		15,747
2022	15,557		15,557
2023	15,335		15,335
Thereafter	71,639		71,639
Total lease payments	151,448		151,448
Less: imputed interest	(58,993)		(58,993)
Present value of lease liabilities	92,455		92,455
Lessor
Lease income	$ 1,522	$ 1,472	$ 3,040	$ 2,945