Leases - Summary of Maturity Analysis of Operating and Finance Lease Liabilities and Reconciliation of Undiscounted Cash Flows (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Operating lease payments due:
Within one year	$ 1,942
After one but within two years	1,909
After two but within three years	1,660
After three but within four years	1,602
After four but within five years	1,212
After five years	4,466
Total undiscounted cash flows	12,791
Discount on cash flows	(1,591)
Total lease liability	11,200	$ 12,544
Finance lease payments due:
Within one year	217
After one but within two years	217
After two but within three years	217
After three but within four years	252
After four but within five years	259
After five years	3,732
Total undiscounted cash flows	4,894
Discount on cash flows	(1,427)
Total lease liability	$ 3,467	$ 3,551