Leases Operating Lease, Other Disclosure (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2019	Dec. 31, 2018
Related Party Transaction [Line Items]
Fixed lease cost	$ 7,350	$ 14,926
Short-term lease cost	353	810
Variable lease cost	661	1,032
Total lease cost	8,364	16,768
Current lease liability	22,477	22,477	$ 0
Long-term lease liability	146,726	146,726	0
Right-of-use asset	$ 167,456	167,456	$ 0
Operating cash flows from operating leases		$ 12,026
Weighted average remaining lease term (years)	8 years	8 years
Weighted-average discount rate	4.10%	4.10%
Third Party Leases
Related Party Transaction [Line Items]
Fixed lease cost	$ 4,762	$ 9,583
Short-term lease cost	353	810
Variable lease cost	661	1,032
Total lease cost	5,776	11,425
Current lease liability	14,480	14,480
Long-term lease liability	92,411	92,411
Right-of-use asset	$ 105,143	105,143
Operating cash flows from operating leases		$ 6,663
Weighted average remaining lease term (years)	7 years	7 years
Weighted-average discount rate	4.00%	4.00%
Seabrook Logistics, LLC [Member] | Equity Method Investee [Member] | Related Party Leases
Related Party Transaction [Line Items]
Fixed lease cost	$ 2,588	$ 5,343
Short-term lease cost	0	0
Variable lease cost	0	0
Total lease cost	2,588	5,343
Current lease liability	7,997	7,997
Long-term lease liability	54,315	54,315
Right-of-use asset	$ 62,313	62,313
Operating cash flows from operating leases		$ 5,363
Weighted average remaining lease term (years)	9 years	9 years
Weighted-average discount rate	4.20%	4.20%