Summary of Significant Accounting Policies - Additional Information (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2019 USD ($) Segment	Mar. 26, 2018 shares	Apr. 30, 2017 ft²	Jan. 31, 2017 ft²
Summary Of Significant Accounting Policies [Line Items]
Spin-off completed date	Mar. 26, 2018
Common stock distribution ratio at spin-off	13.33%
Common stock shares distributed at spin-off | shares		10,266,613
Operating segments | Segment	1
Right of use assets	$ 2,939
Total operating lease obligation	$ 3,282
Operating leases rentable square feet | ft²			6,003	21,020
Operating lease agreement			90 months	89 months
Operating lease, existence of option to extend	true
Operating lease, extended term			60 months
Weighted average remaining operating lease	5 years 7 months 6 days
ASU 2016-02
Summary Of Significant Accounting Policies [Line Items]
Right of use assets	$ 3,000
Total operating lease obligation	$ 3,400