Leases - Summary of Maturity Analysis of Operating and Finance Lease Liabilities and Reconciliation of Undiscounted Cash Flows (Details) $ in Thousands	Jun. 30, 2019 USD ($)
Operating lease payments due:
Within one year	$ 1,075
After one but within two years	1,965
After two but within three years	1,603
After three but within four years	1,464
After four but within five years	1,245
After five years	6,691
Total undiscounted cash flows	14,043
Discount on cash flows	(2,060)
Total lease liability	11,983
Finance lease payments due:
Within one year	108
After one but within two years	216
After two but within three years	217
After three but within four years	217
After four but within five years	217
After five years	4,244
Total undiscounted cash flows	5,219
Discount on cash flows	(1,628)
Lease liability	$ 3,591