Leases - Schedule of Balance Sheet Operating Leases (Detail) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Assets:
Operating lease right-of-use asset	$ 131	$ 227
Liabilities:
Operating lease liabilities, current portion	120	113
Operating lease liabilities, long term portion	24	144
Total operating lease liabilities	$ 144	$ 257