Leases - Operating and Finance Lease Right-of-use-assets and Related Lease Obligations (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Leases
Operating lease assets	$ 9,403	$ 9,242
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]	Operating lease assets	Operating lease assets
Finance lease assets	$ 18,914	$ 19,238
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]	Finance lease assets	Finance lease assets
Total leased assets	$ 28,317	$ 28,480
Operating liabilities current	$ 5,106	$ 4,716
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]	Other Liabilities, Current	Other Liabilities, Current
Finance liabilities current	$ 1,039	$ 979
Finance Lease, Liability, Current, Statement of Financial Position [Extensible List]	Finance liabilities current	Finance liabilities current
Operating liabilities noncurrent	$ 4,170	$ 4,357
Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	Other Liabilities, Noncurrent	Other Liabilities, Noncurrent
Finance liabilities noncurrent	$ 46,128	$ 46,415
Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	Finance liabilities noncurrent	Finance liabilities noncurrent
Total lease liabilities	$ 56,443	$ 56,467
Operating Lease, Liability, Statement of Financial Position [Extensible List]	Other Liabilities, Current, Other Liabilities, Noncurrent	Other Liabilities, Current, Other Liabilities, Noncurrent
Finance lease, accumulated depreciation	$ 48,900	$ 48,600
Prepaid financing costs	$ 600	$ 700