Leases - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Jan. 01, 2019	Dec. 31, 2018
Leases [Abstract]
Cumulative effect of new accounting principle in period of adoption		$ 5,500
Operating lease liabilities	$ 1,176	1,600
Operating lease liabilities, long-term	3,189	$ 3,900
Lease expense recognize on a straight-line basis	500
2019	1,412		$ 2,000
2020	1,369		1,500
2021	621		800
2022	327		50
2023	200		400
After 2023	$ 2,922		$ 4,200