Leases - Summary of Lease Cost and Cash Flow Information (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Lease Cost
ROU operating lease cost	$ 2,666		$ 6,115
Short-term Lease, Cost	3,734		6,485
Finance Lease Cost:
Amortization of ROU assets	4,418,000		9,912,000
Finance Lease, Interest Expense	1,142,000	$ 515,000	2,249,000	$ 1,039,000
Total finance lease cost	5,560,000		12,161,000
Cash paid for amounts included in the measurement of lease liabilities
Operating cash flows from operating leases	6,400		12,610
Financing cash flows from finance leases	$ 8,812,000		$ 16,273,000