Leases - Operating and Finance Lease Assets and Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Assets
Operating lease assets	$ 12,951	$ 6,892
Financing lease right-of-use assets	16,795	15,842
Total lease assets	29,746	22,734
Current liabilities:
Current operating lease liabilities	2,181	1,885
Current financing lease liabilities	45	6,593
Current lease liabilities	2,226	8,478
Noncurrent liabilities:
Long-term operating lease liabilities	11,467	5,643
Long-term finance lease liabilities	72	112
Total lease liabilities	$ 13,765	$ 14,233