Leases - Components of Lease Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Leases [Abstract]
Operating lease cost	$ 801	$ 688	$ 1,594	$ 1,866
Finance lease cost:
Amortization of leased assets	2,943	2,120	8,859	7,950
Interest on lease liabilities	315	786	1,403	1,194
Net lease cost	$ 4,059	$ 3,594	$ 11,856	$ 11,010