Commitments and Contingencies (Tables)

12 Months Ended

Dec. 31, 2018

Commitments And Contingencies Disclosure [Abstract]

Summary of Future Annual Minimum Lease Payments Due Under Non-cancellable Operating Leases

Future annual minimum lease payments due under non-cancellable operating leases at December 31 of each year are as follows (in thousands):

2019	$	397
2020		409
2021		83
Thereafter		—
Total minimum lease payments	$	889