Leases - Summary of Lease Cost and Cash Flow Information (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Lease Cost
Operating lease cost	$ 3,180	$ 3,067	$ 9,437	$ 8,969
Short-term Lease, Cost	2,441	2,465	7,614	6,293
Finance Lease Cost:
Amortization of leased assets	5,141,000	4,109,000	16,068,000	16,506,000
Finance Lease, Interest Expense	1,833,000	927,000	3,441,000	2,852,000
Total finance lease cost	6,974,000	5,036,000	19,509,000	19,358,000
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows from operating leases	5,621	5,850	17,256	16,201
Financing cash flows from finance leases	$ 7,944,000	$ 8,557,000	$ 22,970,000	$ 20,171,000