Commitments and Contingencies - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Commitments And Contingencies Disclosure [Abstract]
Operating leases, abandonement expense, net		$ 200,000
Operating Lease, Liability, payments due	$ 0
Rent expense	$ 400,000	$ 300,000